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Once bitten, twice shy

An injury makes a person wary of its cause.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Idioms and Phrases with once bitten, twice shy

once bitten, twice shy

Once hurt, one is doubly cautious in the future, as in He was two days late last time, so she's not hiring him again—once bitten, twice shy. This seemingly old observation, presumably alluding to an animal biting someone, was first recorded in 1894.

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