I'm thinking of a word that rhymes with "alien."

I love self-descriptive terms. I explain to newbies at work that they have to master their TLAs in order to understand what others are talking about. Not that that's a clue or anything. Crambo's word, which is a bit lengthier than our last word, seems somewhat appropriate for our game.

A screenwriter who doesnʻt shy away from a clicheʻ might
write:
-- "THAT was
__ __ __ __!!"

-- "THIS is NOW!!!"

Not then. I should clarify that Crambo's word rhymes with all of "alien."

Not: then

Well, on this one, the 1st syllable might count only as
assonance, not rhyme:
Proverb:
"A naerr is fun a naerr
a __ __ __ __ __.* / One
fool is an expert on another."

*My Yiddish spelling may be substandard, but my online dictionary
says "__ __ __ __ __" is
an English word,too, since the 1960s, with the meaning
"an informal , or self-appointed expert".

Formally and officially, I did not describe myself. That was the work of Linnaeus.

You say the word is a bit lengthier than frock, but that makes me wonder if the word is so long, ponderous and polysyllabic that one might say it's a foot and a half long.

Whenever I come up with one of these obscure words, James nails it on his first guess! Crambo's word was indeed sesquipedalian. Ordinarily I would work on answers for Roland's Yiddish and Tess's taxonomic term, but today I'm swamped with work so I'll ask them to supply the answers. Congrats, James, and over to you!

"Rolandʻs Yiddish. . .term"
(4, 7)
That was "maven" (English spelling). I was thinking of only a disyllable at the time.
No 1st syll. L, so I noted that it might only be assonance.
"Tessʻ taxonomic term"
(5. 7)
I donʻt know, but Iʻm curious.

Let's see if the next round goes as quickly...

New game HERE

Tess's taxonomic term=mammalian

Thanks, Tess.

Good one, Tess. Not sure why that didn't occur to me. I was pretty frazzled over the weekend.