Boisterous, did swirl whip outside (7)
I believe the answer is:
laddish
'boisterous' is the definition.
(I've seen this before)
'did swirl whip outside' is the wordplay.
'swirl' indicates anagramming the letters (I've seen 'swirling' mean this).
'whip' becomes 'lash' (synonyms).
'outside' means one lot of letters goes inside another.
'did' is an anagram of 'ddi'.
'ddi' placed within 'lash' is 'LADDISH'.
(Other definitions for laddish that I've seen before include "How like a boy" , "typical of boys" , "Given to immature and aggressive behaviour" , "Like a young man" , "Immature and rowdy" .)