Answer: fortifying

AnswerCrossword Clue
fortifyingStrengthen (a place) with defensive works so as to protect it against attack
fortifyingStrengthen or invigorate (someone) mentally or physically
fortifyingStrengthen (a drink) with alcohol
fortifyingIncrease the nutritive value of (food), esp. with vitamins
fortifyingFORTIFY, to strengthen against attack