\Rob"ber\, n. One who robs; in law, one who feloniously takes goods or money from the person of another by violence or by putting him in fear. Some roving robber calling to his fellows. --Milton. Syn: Thief; depredator; despoiler; plunderer; pillager; rifler; brigang; freebooter; pirate. See {Thief}. {Robber crab}. (Zo["o]l.) (a) A purse crab. (b) Any hermit crab. {Robber fly}. (Zo["o]l.) Same as {Hornet fly}, under {Hornet}. {Robber gull} (Zo["o]l.), a jager gull.