# Illusory vs Illusionary? **URL:** \ **Category:** Factual Questions\ **Created:** [July 30, 2013, 5:13pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923 "2013-07-30T17:13:16Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [July 30, 2013, 5:13pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/1 "2013-07-30T17:13:16Z")
I am having trouble categorizing the use of these synonyms; dictionaries aren’t much help. In a similar context to what I’m writing about, would you say that unworkable and ineffective solutions to global climate change are illusionary or illusory? ---
**Author:** ![leahcim](https://avatars.discourse-cdn.com/v4/letter/l/b4bc9f/32.png) [@leahcim](https://boards.straightdope.com/u/leahcim)\ **Post date:** [July 30, 2013, 5:20pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/2 "2013-07-30T17:20:18Z")
Illusionary seems to be a more obscure variant. [m-w.com](http://m-w.com) seems to just redirect to Illusory. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [July 30, 2013, 5:38pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/3 "2013-07-30T17:38:46Z")
> [@Amateur\_Barbarian](#): > > would you say that unworkable and ineffective solutions to global climate change are illusionary or illusory? I wouldn’t say either, but maybe I’m missing what you’re trying to get across. If a solution is unworkable and ineffective, that doesn’t make it _illusory_. That makes it a failure. The dream/goal/objective of a workable, effective solution to global climate change may be illusory, however. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 30, 2013, 5:53pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/4 "2013-07-30T17:53:42Z")
An [ngrams search](http://books.google.com/ngrams/graph?content=illusory%2Cillusionary&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=) shows that illusory is used 20 times more than illusionary. Illusionary is much newer. Probably it has no more meaning than the pedantic effect of sticking in an extra syllable, a trend in current English. The quotes from the books listed don’t show much difference in the use of the two words. I doubt that there is any useful distinction, unless some academic discipline has adopted illusionary as jargon. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [July 30, 2013, 9:08pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/5 "2013-07-30T21:08:55Z")
In my head, “illusionary” describes stage magicians (illusionists) or their performances. I don’t really expect anyone else to use the same definition, but that’s always the first thing I think of. Illusory is just anything that’s an illusion, deceptive or imagined. For the specific context of ineffective approaches to global warming, I wonder if a term like delusional might be better, since it is characterized by “false or unrealistic beliefs” or “belief held with strong conviction despite evidence to the contrary.” ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [July 30, 2013, 9:23pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/6 "2013-07-30T21:23:27Z")
Helpful, thanks. I’ve always used “illusionary” but for no specific reason. Illusory fits better in the place I’m questioning. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [July 30, 2013, 10:10pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/7 "2013-07-30T22:10:32Z")
I didn’t know “illusionary” was even a word. If I saw it somewhere I would assume it was an error. (My Firefox spellchecker agrees with me, I see, by putting a little wavy red line under it.) ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [July 30, 2013, 11:19pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/8 "2013-07-30T23:19:06Z")
It’s a bit like the disassociate/dissociate pair. Both are words, one’s more common, for some reason I acquired usage of the lesser-used one. ---
**Author:** ![leahcim](https://avatars.discourse-cdn.com/v4/letter/l/b4bc9f/32.png) [@leahcim](https://boards.straightdope.com/u/leahcim)\ **Post date:** [July 31, 2013, 1:32am UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/9 "2013-07-31T01:32:46Z")
> [@Amateur\_Barbarian](#): > > It’s a bit like the disassociate/dissociate pair. This is probably because “associate” is descended from a word that had a prefix (ad + sociare), but the raw stem has not been handed down to us, so we don’t think of the modern word as having a prefix. If, when constructing the “dis-” form, you treat “associate” as being a stem with a prefix, you remove the old prefix before attaching the new one and get “dissociate”. If you treat “associate” as not having a prefix, you get “disassociate”. Come to think of it “Illusory” and “Illusionary” is the same thing with suffixes. If you treat “illusion” as being a stem with a suffix, then “illusory” is a different suffix on the same stem. If you treat it as a full word unto itself, you just tack the suffix onto the end and get “illusionary”. ---
**Author:** ![moriah](https://avatars.discourse-cdn.com/v4/letter/m/b2d939/32.png) [@moriah](https://boards.straightdope.com/u/moriah)\ **Post date:** [July 31, 2013, 8:07am UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/10 "2013-07-31T08:07:05Z")
If it pertains to an illusion, it’s illusionary. If it’s similar to an illusion, it’s illusory. “After dropping acid, the illusionary reflections in the window triggered far more disconcerting illusory images.” ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [July 31, 2013, 8:31am UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/11 "2013-07-31T08:31:03Z")
> [@moriah](#): > > If it pertains to an illusion, it’s illusionary. > > If it’s similar to an illusion, it’s illusory. > > “After dropping acid, the illusionary reflections in the window triggered far more disconcerting illusory images.” Maybe you are onto something with this distinction, but I don’t understand your example. Reflections are not illusions (at least, not unless you misinterpret them as being something else). ---
**Author:** ![Deegeea](https://avatars.discourse-cdn.com/v4/letter/d/e9bcb4/32.png) [@Deegeea](https://boards.straightdope.com/u/Deegeea)\ **Post date:** [July 31, 2013, 4:08pm UTC](https://boards.straightdope.com/t/illusory-vs-illusionary/664923/12 "2013-07-31T16:08:15Z")
To my perception, the difference is slight but there is one. You can replace " \_\_\_\_ is illusionary " with " \_\_\_\_\_\_ is an illusion " and have nearly identical meaning. But with a difference of remove (and in some contexts), I’d instead replace " \_\_\_\_\_\_ is illusory " with " \_\_\_\_\_\_ is like an illusion " So to me, illusionary means having the definitional quality of an illusion, while illusory can have that meaning, but it has another closely related sense, in which it means having some (perhaps connotational) qualities of an illusion, or being like an illusion (usually in addition to being an illusion, rather than instead of, but either is possible). Calling a dream “illusionary” would be redundant, while calling a dream “illusory” would be descriptive. The latter would give an impression that the dream felt dreamlike - many dreams feel real while you’re dreaming them, but none actually are really happening.