catch a crab
v. phr.— «And they oohed with disappointment when another boat stopped dead in the water as one of the rowers “caught a crab” as they say in the sport: An oar caught water and was pulled downward resulting in an urgent need to halt the boat.» —“They pull for East Hartford High” by John Karas East Hartford Gazette (Connecticut) Oct. 30, 2008. (source: Double-Tongued Dictionary)
Further reading
Susan from Virginia Beach, Virginia, shares the phrase her mother used when the kids refused to eat: It’ll grow hair on your back teeth. This supposed motivator likely blends two older traditions: a German idiom, Haare auf den Zähnen haben...
Why do speakers of the same language have different accents? A lively new book called Why We Talk Funny offers a linguist’s look at how and why accents develop. And: If you’ve “stood up” at a wedding, were you supporting the marriage or objecting to...
This phrase appears in “Through the Looking Glass”, Chapter 5 (in which Alice suddenly finds herself rowing in a boat with the Sheep):
“‘Feather! Feather!’ the Sheep cried again, taking more needles. ‘You’ll be catching a crab directly.'”
alot of older inmates use it on the newer inmates “catch a crab”,
seeking out fresh meat or punk them out.