Life dependency needs one to be this (3)
I believe the answer is:
fed
'one to be this' is the definition.
The definition suggests a singular noun which matches the answer.
'life dependency needs' is the wordplay.
'needs' says the answer is hidden in the clue.
'FED' can be found hidden inside 'life dependency'.
Can you help me to learn more?
(Other definitions for fed that I've seen before include "US agent" , "Banking authority" , "Dished up food" , "American cop" , "Given sustenance" .)