Get on in the sack — produce baby? (5)
I believe the answer is:
breed
'get' is the definition.
(thesaurus)
'on in the sack produce baby?' is the wordplay.
I cannot quite see how this works, but
'on' could be 're' ('on' can be mean 'with reference to') and 're' is found in the answer.
'sack' could be 'bed' ('in the sack' means 'in bed') and 'bed' is located in the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for breed that I've seen before include "Livestock classification" , "Procreate" , "Mate specific animals to produce certain qualities" , "Rear; variety" , "Lead to (success); kind" .)