Strapped river’s swans in the wings (9)
I believe the answer is:
penniless
'strapped' is the definition.
The answer and definition are not the same part of speech. However, adjectives and past participle verbs can occasionally define each other.
'river's swans in the wings' is the wordplay.
I cannot quite understand how this works, but
'river's' could be 'niles' (Nile is an example) and 'niles' is found within the answer.
'swans' could be 'pens' (pen is a kind of swan) and 'pens' is found within the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for penniless that I've seen before include "Poverty-stricken" , "Broke" , "Cleaned out" , "Not rich" , "Without money, not a cent" .)