To strengthen.
To accumulate, to pile up, to increase in stages.
To close up by building.
In solitaire card games, to place a card over another card of lower value. (e.g., place 5♦ over 4♣)
To erect; to construct.
To motivate, to instill someone with determination.
To recharge, to give electrical power to something.
To deliberately infect an individual with HIV as part of bug-chasing.