A short time before Gaelic came to be (5)

I believe the answer is:

terse

I'm a little stuck... Click here to teach me more about this clue!

'came to be' is the definition.
I can't tell whether this definition defines the answer.

'a short time before gaelic' is the wordplay.
'a short time' becomes 't' (abbreviation for time).
'before' means one lot of letters go next to another.
'gaelic' becomes 'erse' (synonyms).
't'+'erse'='TERSE'

Can you help me to learn more?

(Other definitions for terse that I've seen before include "Aphoristic" , "Using few words" , "Brusque and curt" , "Short and succinct" , "Compact" .)

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.