Fortified (12)
'fortified' is the definition.
('strengthen' can be a synonym of 'fortify')
This is the entire clue.
(Other definitions for strengthened that I've seen before include "Reinforced" , "Made more robust" .)
'fortified' is the definition.
('beef up' can be a synonym of 'fortify')
This is all the clue.
(Other definitions for fed that I've seen before include "Dished up food" , "Provided courses" , "Given sustenance" , "American cop" , "Gave food to (someone)" .)