No science subjects mean breaking into so much laughter (4,4)
I believe the answer is:
fine arts
'no science subjects' is the definition.
'mean breaking into so much laughter' is the wordplay.
'mean' becomes 'near' (both can mean miserly).
'breaking into' means one lot of letters goes inside another.
'so much laughter' becomes 'fits'.
'near' placed into 'fits' is 'FINE ARTS'.
(Other definitions for fine arts that I've seen before include "sophisticate's bag" , "Those appreciated for their beauty" , "Fan tries to get painting sculpture etc" , "paintings and poetry etc" , "Creative works appealing to sense of beauty" .)