Sandbag
noun
A sturdy sack filled with sand, generally used in large numbers to make defensive walls against flooding, bullets, or shrapnel.
A small bag filled with sand and used as a cudgel.
An engraver's leather cushion, etc.
verb
To construct a barrier of sandbags around.
“We sandbagged the basement windows against the floodwaters.”
To strike someone with a sandbag or other object to disable or render unconscious.
To conceal or misrepresent one's true position, potential, or intent in order to gain an advantage.