A crab is any of various crustaceans with four pairs of legs, a pair of pincers, a flattish shell, and a short, broad abdomen folded under its thorax.

  • Purse crab
  • Fiddler crab
  • Mole crab
  • Horshoe crab
  • Lady crab
  • Oyster crab
  • Spider crab
  • Stone crab
  • Ghost crab
  • Hermit crab
  • Blue crab

Several similar animals, such as the crab louse, or the hermit crab, are also called crabs.

"Crabs" is a slang term for pubic lice.

A crab is any of various machines used to hoist heavy objects.