Counsellor is taken in by part of speech, almost (7)
I believe the answer is:
adviser
'counsellor' is the definition.
(I've seen this before)
'is taken in by part of speech almost' is the wordplay.
'taken in by' is an insertion indicator.
'part of speech' becomes 'adverb' (adverb is a kind of part of speech).
'almost' means to remove the last letter (most of the word but not all of it).
'adverb' with its last letter taken away is 'adver'.
'is' placed inside 'adver' is 'ADVISER'.
(Other definitions for adviser that I've seen before include "Counsellor, mentor" , "Counseller" , "Guide" , "subject's specialist consultant" , "ID saver (anag.)" .)