Indigent, being reduced in rank? (3)
I believe the answer is:
gen
'rank?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'indigent being reduced' is the wordplay.
'being reduced' indicates a hidden word (reducing the letters in the clue shows the answer).
'GEN' is hidden within 'indigent'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for gen that I've seen before include "'Information, colloquially (3)'" , "Info" , "Information yielded" , "Information (colloq.)" , "Knowledge" .)