Inclined to produce nitrogen (5)
I believe the answer is:
given
'inclined to' is the definition.
(thesaurus)
'produce nitrogen' is the wordplay.
'produce' becomes 'give' (giving is a kind of producing).
'nitrogen' becomes 'N' (N is the chemical symbol for nitrogen).
'give'+'n'='GIVEN'
(Other definitions for given that I've seen before include "Awarded" , "supplied" , "Specified - granted" , "Donated" , "Handed over; an 18 dn" .)