CRAB, or GRAB, a disagreeable old person. _Name of a wild and sour fruit._ “To catch a CRAB,” to fall backwards by missing a stroke in rowing. CRAB, to offend, or insult; to expose or defeat a robbery, to inform against. CRABSHELLS, or TROTTING CASES, shoes.—_See_ CARTS. CRACK, first-rate, excellent; “a CRACK HAND,” an adept; a “CRACK article,” a good one.—_Old._