Wonderful going around foremost of night spots (4)
I believe the answer is:
acne
'spots' is the definition.
(I've seen this before)
'wonderful going around foremost of night' is the wordplay.
'wonderful' becomes 'ace'.
'going around' indicates putting letters inside.
'foremost of' indicates taking the first letters.
The first letter of 'night' is 'n'.
'ace' placed around 'n' is 'ACNE'.
(Other definitions for acne that I've seen before include "Pimply skin condition of adolescence" , "Inflammation of glands in skin" , "(Inflammation causing) spots" , "Teenage skin blemish" , "Youthful problem" .)