1. slang A person swimming or surfing alone in the ocean. We sat on the beach with our drinks, watching the foolish shark bait going into the water alone for an evening swim.

2. (Hawaii slang) A very pale beachgoer, especially a tourist. (Supposedly because pale skin is attractive to sharks.) We don't hang out in this part of town too often in the summer, as it gets overwhelmed with shark bait this time of year.

3. A particularly naïve or gullible person who is an ideal target for a scam, graft, or con. He'd been in the game of scamming people for so long that he could spot shark bait from a mile away. Don't you dare wear that fanny pack out in town. We'll look like shark bait to the locals!