Stray remark that’s critical over topless robe (7)
I believe the answer is:
digress
'stray' is the definition.
(synonyms)
'remark that's critical over topless robe' is the wordplay.
'remark that's critical' becomes 'dig' (dig can mean a nasty or insinuating comment).
'over' is a charade indicator (letters next to each other).
'topless' means to remove the first letter.
'robe' becomes 'dress' (I've seen this before).
'dress' with its initial letter taken off is 'ress'.
'dig'+'ress'='DIGRESS'
(Other definitions for digress that I've seen before include "Go off the main subject" , "Leave the point" , "Wander from one's path" , "Wander from a topic" , "Wander from subject" .)