Release English girl with one leg (8)
I believe the answer is:
emission
'release' is the definition.
(something emitted)
'english girl with one leg' is the wordplay.
'english' becomes 'e' (abbreviation).
'girl' becomes 'miss' (term of address for an unmarried woman).
'with' says to put letters next to each other.
'one' becomes 'i' (Roman numeral).
'leg' becomes 'on' (cricket term, fielding positions).
'e'+'miss'+'i'+'on'='EMISSION'
(Other definitions for emission that I've seen before include "it gets thrown out" , "Release" , "Going out" , "Sending forth" , "issue" .)