sandbag

Short definition from Wiktionary

Noun

1. 1
   A sturdy sack filled with sand, generally used in large numbers to make defensive walls against flooding, bullets, or shrapnel.
2. 2
   A small bag filled with sand and used as a cudgel.
3. 3
   An engraver's leather cushion, etc.
4. 4
   A deceptive play whereby a player with a strong hand bets weakly or passively.

Verb

1. 1
   To construct a barrier of sandbags (around).
2. 2
   To strike someone with a sandbag or other object to disable or render unconscious.
3. 3
   To conceal or misrepresent one's true position, potential, or intent in order to gain an advantage; (originally poker) to pretend to have a weak hand, as a strategy.
4. 4
   To blindside; to deceive; to undermine.
5. 5
   To premake dishes (prepare them in advance) (intransitive); to premake (dishes) (transitive).
6. 6
   To pretend to drink alcohol early on so that, as the night draws on, one can drink everybody else "under the table".