a venomous spider, Latrodectus mactans, widely distributed in the U.S., the female of which is jet-black with an hourglass-shaped red mark on the underside of its abdomen.
Origin of black widow
First recorded in 1910–15
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for black widow
an American spider, Latrodectus mactans, the female of which is black with red markings, highly venomous, and commonly eats its mate
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012