sandbag (Noun) — A bag filled with sand; used as a weapon or to build walls or as ballast.
sandbag (Verb) — Treat harshly or unfairly.
sandbag (Verb) — Compel by coercion, threats, or crude means. ex. "They sandbagged him to make dinner for everyone"
sandbag (Verb) — Hit something or somebody as if with a sandbag.
sandbag (Verb) — Downplay one's ability (towards others) in a game in order to deceive, as in gambling.
sandbag (Verb) — Protect or strengthen with sandbags; stop up. ex. "The residents sandbagged the beach front"