One engaged in theft, if unfortunate, will get 2% (8)
I believe the answer is:
fiftieth
'2%' is the definition.
(2 per cent is one fiftieth)
'one engaged in theft if unfortunate' is the wordplay.
'one' becomes 'i' (Roman numeral).
'engaged in' means one lot of letters goes inside another.
'unfortunate' is an anagram indicator.
'theft'+'if'='theftif'
'theftif' is an anagram of 'fifteth'.
'i' going into 'fifteth' is 'FIFTIETH'.
'will get' is the link.
(Other definitions for fiftieth that I've seen before include "Gold anniversary" , "This anniversary is golden" .)