inspired by this thread, which got me into quite a nitpicking mood based on the number of examples posted of 4 and 5 syllable words that don’t actually rhyme. I decided to set them straight with some real examples- except my brain seems to have shut down and I couldn’t think of any. Easy, I thought, I’ll just look up 4 and 5 syllable rhyming words on google. But no! Unbelievable as it may seem, unfathomable really, nowhere could I find any list whatsoever of words that rhyme with 4 or more syllable. Using all sorts of term combinations, I found absolutely nothing, no list, no mentions of lists, not even a mention of a pair of long words that rhyme. (true rhyme). Got me thinking, whats the longest rhyming words in the English Language? Surely that info must be on the net, or even at least proposed by somebody? Nope. Nobody in the world seems to have pondered this question online before. These random inexplicable absences of information on the net that I happen to specifically be looking for frustrate me to the point of obsession and ultimately total unproductivity. So I need to know, does anyone here know a) what the longest rhyming words are, and b)where a list,(any list, even if it’s just 2 words dammit) of high syllable rhyming words can be found ? and ( and c) more for my personal frustration, how is it possible that hundreds of people haven’t talked about high syllable rhyming words before on the internet??? what is wrong with the word obsessed online population that they wouldnt be interested in this!!??)
Luminosity
Numinosity
Probably not the answer, but I’ve always admired Robert Palmer’s “Simply Irresistible” for its wonderful repeated use of triple and longer rhymes (“Her methods are inscrutable/The proof is irrefutable”). Though it’s not a song that moves me emotionally, it’s definitely a tour de force of using a technically difficult rhyme scheme and making it work without seeming forced.
Do they have to have the same number of syllables?
If not – antidisestablishmentarianism and contrarianism.
What constitutes words that actually ryhme?
Chemistry can provide many examples. Off the top of my head, both 7 syllables:
Methoxycyclohexane
Ethoxycyclohexane
(I know, I know, these aren’t the IUPAC names, but c’mon, they rhyme!)
That’s what I mean, though yeah, scientific words don’t have much function in the world of rhyming. What I’m specifically not looking for are words that almost rhyme, or simply have only the second have of the word ryhme, this is what was going on in the previously mentioned thread that got me looking to begin with!
**cjepsons **example of antidisestablishmentarianism and contrarianism, in my mind, don’t rhyme, more for different vowel sounds happening in each than the differing syllables.
I think you are going to have to define what you mean by “rhyme.” Do you mean all syllables except the first one must rhyme? And is it by pronunciation or spelling?
Well, a “perfect” rhyme (which is what I believe most people using the word “rhyme” casually are referring to) is considered to be one in which the final stressed syllable and any following unstressed syllables are identical (minus the leading consonant sound). They are generally subdivided into three categories: masculine, feminine, and dactylic.
Masculine: heart, tart
Feminine: Mellow, yellow
Dactylic: Retractable, distractable
So, antidisestablishmentarianism and contrarianism are examples of perfect rhymes. (Actually, I don’t know what that would be called, since it ends on a stressed syllable followed by three unaccented syllables, at least the way I scan it.)
Wow, I didn’t know that! Thanks…
so are Beheaded and Unleaded are actually perfect rhymes?
In my mind, ‘beheaded’ and ‘deleaded’ are better rhymes, because all syllabols rhyme.
and, what is a word called that has every syllable rhyme, no matter where the accent is?
Yes.
I don’t know. But your definition needs a little refining, as you have two different consonant pairs going on there “be” and “de” along with “head” and “lead.” Perfect rhymes require that unaccented syllables are identical, while the accented syllable differs by the initial consonant sound, thereby “deleted” and “defeated” might be a better example for what you’re looking for. Although I don’t know if there’s a special name for this type of extended perfect rhyme.
pulykamell’s definition is brilliant. For a fun nitpick, though, note that this is only strictly true for English. In Welsh, for example, it is okay (and in some verse forms, required) to rhyme a stressed syllable with an unstressed syllable (tráserch, “lust,” rhymes with mérch, “girl / young woman”). Irish is even more complex:
“For rhyme the stressed vowels must be identical, and every consonant after the stressed vowel must be of the same class and quality each to each. The consonants are divided into six classes: (1) b, d, g; (2) p, t, c; (3) ph / f, th, ch; (4) bh, dh, gh, l, mh, n, r; (5) ll, mm, nn, ng, rr; (6) s. A consonant rhymes only with one of its own class, and palatal rhymes only with palatal, non-palatal with non-palatal.” (Myles Dillon, Early Irish Literature, re-punctuated for clarity.)
So rhyming pairs in Irish are fainnghréine and maighshléibhe*, a little like “fahn-RAIN-yuh” and “my-LAYV-yuh”: those just don’t sound like a rhyme in English, while words like ball and bal would not rhyme because the [L]s are not considered as similar to each other as to the other consonants in their class.
*Lines 1363 and 1365 of Buile Shuibhne, if anyone cares to verify.
[slight tangent]
Oh, yes, different languages certainly have different standards for this sort of euphony, partly because of the stress patterns, grammars, and sounds of different languages. Even English has a sliding scale. The definition I gave only applies to “perfect rhymes.” Many, if not most, modern poets applying rhyme use similarly euphonic, but more subtle rhymes, where consonants and even vowel sounds may differ slightly, but be similar enough to imply a sense of harmony. Assonance (identities of vowel sounds) has become quite popular for end-rhyming and, in my opinion, often lends a more serious, less sing-songy tone to rhymed verse than strict perfect rhymes.
[/slight tangent]
Yeah, but how often are those words likely to show up in a poem, anyway? 
Rather often 
— This particular example is actually from medieval Wales’s greatest poet, Dafydd ap Gwilym, in his poem to his penis. link: go to poem #85 (Y Gal) You can read the translation or hear the original read aloud. He has many non-pornographic poems, too.
Sigh. No one has yet mentioned probably the most famous one:
Supercalifragilisticexpialidocious
Okay, I’m going.
Probably because the sound of it is something quite atrocious.
A surprisingly common subject of poetry, actually. Catullus had a few poems along those lines, too.
I owe my knowledge of Latin swear words almost entirely to reading Catullus. 
I tend not to think of words as rhyming unless they have the same number of emphasized syllables, in addition to satisfying pulykamell’s definition above. So to my ear “antidisestablishmentarianism” doesn’t rhyme with “contrarianism”.
However, I would consider it a rhyme if you said:
“Antidisestablishmentarianism,
was a policy born of contrarianism.”
That is, the word in line 1 rhymes with the phrase in line 2.
Note they have different numbers of syllables, but the same number of emphasized syllables (meaning the same number of metrical feet, maybe?
)
AN ti dis es TAB lish men TAR i an is m
was a POL i cy BORN of con TRAR i an is m