build%20up

verb

1. 1

   To erect; to construct.

2. 2

   To close up by building.

   “to build up a door”

3. 3

   To accumulate, to pile up, to increase in stages.

   “Ever since the secretary left, the letters in my inbox have started to build up.”

4. 4

   To strengthen.

   “They had to build up their fortress to protect against attack.”

5. 5

   In solitaire card games, to place a card over another card of lower value. (e.g., place 5♦ over 4♣)