Yields and strays — into such transgression? (6,3)
I believe the answer is:
deadly sin
'such transgression?' is the definition.
'deadly sin' can be an answer for 'transgression?' (deadly sin is a kind of transgression). I am not sure about the 'such' bit.
'yields and strays' is the wordplay.
'strays' indicates an anagram.
'yields'+'and'='yieldsand'
'yieldsand' is an anagram of 'DEADLY SIN'.
'into' acts as a link.
(Other definitions for deadly sin that I've seen before include "Anger, say" , "a cause of damnation" , "not good - bad" , "Lethal lapse like pride, gluttony or envy" , "Anger, covetousness, envy, gluttony, lust, pride or sloth" .)