Mr T going missing - tightwad! (5)
I believe the answer is:
miser
'tightwad' is the definition.
(synonyms)
'mr t going missing' is the wordplay.
'mr' becomes 'mister' (Mr is short for Mister).
'going missing' is a deletion indicator.
'mister' with 't' removed is 'MISER'.
(Other definitions for miser that I've seen before include "One of the people who spend least" , "Mean person" , "man, that's close" , "One giving little" , "Stingy type" .)