High-pitched male parts wobble (7)
I believe the answer is:
tremble
'wobble' is the definition.
(thesaurus)
'high-pitched male parts' is the wordplay.
'high-pitched' becomes 'treble' (similar in meaning).
'male' becomes 'm' (common abbreviation).
'parts' means one lot of letters goes inside another (in the sense of cuts or separates).
'treble' placed around 'm' is 'TREMBLE'.
(Other definitions for tremble that I've seen before include "Shiver, quake" , "get the shakes" , "Quake in one's shoes" , "sign of nerves" , "Look nervous" .)