Decorate in black tight red moiré skirts (9)
I believe the answer is:
embroider
'decorate' is the definition.
(I know this)
'black tight red moire skirts' is the wordplay.
'black' becomes 'b' (as in pencil classifications).
'tight' indicates an anagram (tight can mean drunk).
'skirts' indicates putting letters inside (skirt can mean to go around).
'red'+'moire'='redmoire'
'redmoire' with letters rearranged gives 'emroider'.
'b' placed within 'emroider' is 'EMBROIDER'.
'in' acts as a link.
(Other definitions for embroider that I've seen before include "Exaggerate" , "Do decorative needlework" , "Elaborate" , "Dress up" , "stitch" .)