Doing time inside for being infatuated (6)
I believe the answer is:
doting
'being infatuated' is the definition.
(thesaurus)
'doing time inside' is the wordplay.
'time' becomes 't' (abbreviation).
'inside' is an insertion indicator.
'doing' placed around 't' is 'DOTING'.
'for' acts as a link.
(Other definitions for doting that I've seen before include "Devoted" , "Overly fond, as husband may be" , "Showing great fondness as for a spouse" , "Overly fond of, say spouse" , "Showing excessive love" .)