One expects to see them in a row (4)
I believe the answer is:
oars
'a row' is the definition.
Although both the answer and definition are nouns, they are not in the same form of the noun. However, I know that 'row' relates to this answer.
'one expects to see them' is the wordplay.
I cannot really understand how this works, but
'one' could be 'a' (a thing is one thing) and 'a' is present in the answer.
The remaining letters 'ors' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for oars that I've seen before include "Implements of propulsion on water" , "Al --, US gangster" , "Propellers for small boat" , "Implements to propel a boat" , "Henley sportsmen" .)