Protection recommended at first in love affair (6)
I believe the answer is:
armour
'protection' is the definition.
(armour protects a warrior)
'recommended at first in love affair' is the wordplay.
'at first' says to take the initial letters.
'in' indicates putting letters inside.
'love affair' becomes 'amour' (I've seen this before).
The first letter of 'recommended' is 'r'.
'r' going inside 'amour' is 'ARMOUR'.
(Other definitions for armour that I've seen before include "Suit of mail" , "Chain mail, e.g." , "Protection for a fighter" , "Body plate" , "Protective clothing" .)