Chasm making female pull up (4)
I believe the answer is:
gulf
'chasm' is the definition.
(gulf is a kind of chasm)
'female pull up' is the wordplay.
'female' becomes 'f' (abbreviation).
'pull' becomes 'lug' (I've seen this before).
'up' is a reversal indicator (in down clue: letters go upwards).
'f'+'lug'='flug'
'flug' backwards is 'GULF'.
'making' acts as a link.
(Other definitions for gulf that I've seen before include "Wide difference of opinion" , "Deep sea inlet, as between Iran and Saudi Arabia" , "Wide gap; arm of sea" , "Abyss" , "Deep inlet of the sea almost surrounded by land" .)