Mishap caused by stress - I'd go into that (8)
I believe the answer is:
accident
'mishap' is the definition.
(I've seen this before)
'stress i'd go into that' is the wordplay.
'stress' becomes 'accent' (synonyms).
'go into that' means one lot of letters goes inside another.
'accent' enclosing 'id' is 'ACCIDENT'.
'caused by' is the link.
(Other definitions for accident that I've seen before include "Mishap, misadventure" , "Pile-up" , "disaster" , "Chance misfortune or injury" , "Unexpected and unplanned event" .)