Suggest merely going topless (5)
I believe the answer is:
imply
'suggest' is the definition.
(implying is a kind of suggesting)
'merely going topless' is the wordplay.
'merely' becomes 'simply' (synonyms).
'going topless' means to remove the first letter.
'simply' with its first letter taken off is 'IMPLY'.
(Other definitions for imply that I've seen before include "Involve - intimate" , "Insinuate or suggest" , "Insinuate, hint" , "Indicate by suggestion" , "Indicate indirectly" .)