Provide with sustenance (7)
I believe the answer is:
nourish
'provide with sustenance' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nourish that I've seen before include "Keep alive and well with food" , "support" , "Give sustenance to" , "[OPPOSITE OF] starve" , "Nurture, sustain" .)