Ace loads firearm, primarily overseeing animal release (5)
I believe the answer is:
guano
'animal release' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'ace loads firearm primarily overseeing' is the wordplay.
'ace' becomes 'a' (abbreviation).
'loads' is an insertion indicator (some letters are loaded into others).
'firearm' becomes 'gun' (I've seen this in another clue).
'primarily' suggests taking the first letters.
The first letter of 'overseeing' is 'o'.
'a' placed inside 'gun' is 'guan'.
'guan'+'o'='GUANO'
Can you help me to learn more?
(Other definitions for guano that I've seen before include "Touching month turning over" , "Fertiliser (either from bird droppings or artificial)" , "Fertilizer from the waste of seabirds" , "Dung of sea birds" , "business to aid growth" .)