Was he not taken advantage of? (3)
I believe the answer is:
ted
'was he not taken advantage of?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'was he' is the wordplay.
I cannot quite understand how this works, but
'he' could be 'ed' (short for Edward) and 'ed' is found within the answer.
A single letter 't' remains 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 ted that I've seen before include "Edward (dim.)" , "Spread (hay); yob" , "Craggy Island Father" , ". . . Kennedy, Father . . ." , "Boy" .)