What he said as he battered down the door? (5)
I believe the answer is:
inigo
'he battered down the door?' is the definition.
The definition suggests a singular noun which matches the answer.
'what he said as' is the wordplay.
I cannot really see how this works, but
'as' could be 'in' (I've seen this in other clues) and 'in' is found in the answer.
The remaining letters 'igo' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for inigo that I've seen before include "Man" , "- Jones, Eng. architect" , "Jones the (C17) architect" , "Fellow" , "-- Jones, C16-17 English architect" .)