Suggest just heading off (5)
I believe the answer is:
imply
'suggest' is the definition.
(implying is a kind of suggesting)
'just heading off' is the wordplay.
'just' becomes 'simply' (synonyms).
'heading off' means to remove the first letter.
'simply' with its initial letter removed is 'IMPLY'.
(Other definitions for imply that I've seen before include "Insinuate, hint" , "State indirectly" , "Involve - intimate" , "Infer" , "Hint, suggest" .)