Trap bringing about mother’s ruin? (3)
I believe the answer is:
gin
'mother's ruin' is the definition.
(informal term for gin)
'trap bringing about' is the wordplay.
'trap' says the answer is hidden in the clue (I've seen 'trapped' mean this).
'GIN' is hidden in the letters of 'bringing about'.
(Other definitions for gin that I've seen before include "Spirit; cotton machine" , "game of cards" , "Strong drink - trap" , "Alcohol for the snare" , "Trap for snaring small mammals" .)