Put on tie, not wanting, ultimately to go out (3,4)
I believe the answer is:
get into
'put on' is the definition.
(synonyms)
'tie not wanting ultimately to go out' is the wordplay.
'ultimately' says to take the final letters.
'to go out' is an anagram indicator.
The last letter of 'wanting' is 'g'.
'tie'+'not'+'g'='tienotg'
'tienotg' anagrammed gives 'GET INTO'.
(Other definitions for get into that I've seen before include "enter" , "Become involved with" .)