Extra clothing huge and blue (6)
I believe the answer is:
morose
'blue' is the definition.
(blue can mean sad)
'extra clothing huge' is the wordplay.
'extra' becomes 'more' (both can mean additional).
'clothing' means one lot of letters goes inside another (some letters cover up or clothe others).
'huge' becomes 'os' (abbreviation for outsize).
'more' enclosing 'os' is 'MOROSE'.
'and' is the link.
(Other definitions for morose that I've seen before include "Sullen and ill-tempered" , "dark" , "Down in the dumps" , "Gloomy and unsociable" , "blue" .)