Wicked, about fifty, and hairless
I believe the answer is:
bald
'hairless' is the definition.
(similar in meaning)
'wicked about fifty' is the wordplay.
'wicked' becomes 'bad' (associated in meaning).
'about' means one lot of letters goes inside another.
'fifty' becomes 'L' (Roman numeral).
'bad' placed around 'l' is 'BALD'.
'and' acts as a link.
(Other definitions for bald that I've seen before include "Without hair" , "With the tread worn away" , "Lacking hair on the scalp" , "Lacking hair on the head" , "Unadorned" .)