Busy gent, husband running round in circles (2,3,2)
I believe the answer is:
on the go
'busy' is the definition.
('on the go' can be similar in meaning to 'busy')
'gent husband running round in circles' is the wordplay.
'husband' becomes 'h'.
'running round' indicates anagramming the letters.
'in' means one lot of letters goes inside another.
'circles' becomes 'oo' (resembles two O's**).
'gent'+'h'='genth'
'genth' anagrammed gives 'ntheg'.
'ntheg' inserted inside 'oo' is 'ON THE GO'.
(Other definitions for on the go that I've seen before include "Active and energetic" , "Very active (colloq.)" , "ready to start monopoly?" , "Ever busy" , "Active, always doing something" .)