Mostly depended on village’s banks for aid (7)
I believe the answer is:
relieve
'aid' is the definition.
(thesaurus)
'mostly depended on village's banks' is the wordplay.
'mostly' means to remove the last letter (most but not all of the word).
'depended on' becomes 'relied' (I've seen this in another clue).
'banks' means to remove the middle letters (the sides or banks of the word).
'village' with its middle taken out is 've'.
'relied' with its final letter taken off is 'relie'.
'relie'+'ve'='RELIEVE'
'for' acts as a link.
(Other definitions for relieve that I've seen before include "Palliate" , "Take place of" , "Comfort" , "Alleviate pain or stress" , "Break the sameness of" .)