Dictionary.com
definitions

blind side

SEE MORE SYNONYMS FOR blind side ON THESAURUS.COM

noun

the part of one's field of vision, as to the side and rear, where one is unable to see approaching objects.
the side opposite that toward which a person is looking.

Origin of blind side

First recorded in 1600–10
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for blind side

blind side

noun

rugby the side of the field between the scrum and the nearer touchline
the side on which a person's vision is obscured

verb blind-side

(tr) US to take (someone) by surprise
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
Word Origin and History for blind side
n.

"unguarded aspect," c.1600; see blind (adj.). As a verb, also blind-side, blindside, "to hit from the blind side," first attested 1968, American English, in reference to U.S. football tackles.

Online Etymology Dictionary, © 2010 Douglas Harper
Idioms and Phrases with blind side

blind side

see under blind spot.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.