It's used in a row or a sword fight (5)
I believe the answer is:
blade
'a row or a sword fight' is the definition.
I know that 'row' relates to this answer.
'it's' is the wordplay.
I cannot quite see how this works, but
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
The remaining letters 'blad' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'used in' acts as a link.
Can you help me to learn more?
(Other definitions for blade that I've seen before include "cutter" , "See 24 Across" , "Runner on an ice-skate" , "London rail terminus" , "Leaf, of grass, say" .)