Became agitated about banker's ultimate squeeze (7)
I believe the answer is:
embrace
'squeeze' is the definition.
(I've seen this before)
'became agitated about banker's ultimate' is the wordplay.
'agitated' is an anagram indicator.
'about' is an insertion indicator.
'ultimate' says to take the final letters.
The final letter of 'banker' is 'r'.
'became' anagrammed gives 'embace'.
'embace' enclosing 'r' is 'EMBRACE'.
(Other definitions for embrace that I've seen before include "Hug, put arms around" , "affectionate greeting" , "Include (in one's arms)" , "bear-hug?" , "Cuddle" .)