Definition of "crab" []

• Any of various predominantly marine crustaceans of the division Brachyura within the order Decapoda, characterized by a broad flattened cephalothorax covered by a hard carapace with a small abdomen concealed beneath it, short antennae, and five pairs of legs, of which the anterior pair are large and pincerlike. (noun)
• Any of various similar related crustaceans, such as the hermit crab or king crab. (noun)
• A horseshoe crab. (noun)
• A crab louse. (noun)
• Slang Infestation by crab lice. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Speaking about the work he sees himself doing as child and youth advocate, Nieman says he sees young people suffering from what he calls the crab-pot syndrome."
• "A dried-out horseshoe crab is a delicate thing and there's no way it would survive the flight in my checked baggage."
• "Sorry, Tashby but the blue crab is no more in inventory at Super Lake as best I can see."