It’s on the tip of my tongue, but not getting any further. It’s a great word for describing horoscopes–you read them, you’re impressed with how well they describe you, but on closer inspection you realize that they were written so as to be accurate for almost everyone.
Verisimilitude?
How about specious:
Main Entry: spe·cious
1 obsolete : showy
2: having deceptive attraction or allure
3: having a false look of truth or genuineness : sophistic <specious reasoning>
(Merriam-Webster)
Truthiness!
All three of those would apply to a statement which only appears to be true, which is not quite what I’m looking for. What I have in mind is something like advice that appears to be telling you what you need to do, but when you try to figure out exactly what you should do based on that advice, you realize that it’s nothing but generalities and platitudes.
I think Forer’s personality assessment is close enough to work as an example. In brief, students were given a personality test with some number of questions, and then were given the following text as the outcome:
On average, people thought that it was a highly accurate assessment of their own personalities, but really it was just cobbled together from various horoscopes. I’d like to think that a critical reading would’ve made it obvious that this is not specific to any one individual. However, there’s nothing false about it: all of those statements really do apply to every one of us from time to time.
ETA: Inspired by this post, I looked up “platitudinous” and I think it or “bromidic” is pretty close to what I’m looking for. But I could’ve sworn that there was a shorter, more common word.
Wondrous-waffle!
Superficial
Misleading? Deceptive? Delusory?
delusory (http://definr.com/delusory)
adj : causing one to believe what is not true or fail to believe
what is true; “deceptive calm”; “a delusory pleasure”
sophistry
Could you be thinking of vacuous (meaning, as you know, ‘empty’ or ‘lacking in ideas or intelligence’)?
Maybe.
ostensible - “appearing as such but not necessarily so” (but you mean “appearing as such but definitely not”, right?)
That’s the word I thought of.
Slight hijack: Is there a word for ‘on the tip of my tongue’? (And don’t say ‘cunnilingus’. 
)
glossapexverbia?
We always called them weasel words.
Only by acronym: TOT.
tergiversate
evade
equivocate
hedge
waffle
A man may smile, and smile, and be a villain.
Sorry, I used the verb form of the first three. In case anyone wonders, the nouns would be:
tergiversation
evasion
equivocation
That’s what I was going to say.
Bollocks.