Synonyms

off guard

Idioms

Also, off one's guard. Not watchful, easily surprised. It is often put as catch (or be caught) off guard, meaning “take (or be taken) by surprise.” For example, The securities analyst was caught off guard by that financial report, or With any luck the boss will be off guard when I come in late. [Late 1600s] The antonym, on guard or on one's guard, meaning “watchful or prepared, especially to defend oneself,” was first recorded in 1577. For example, In this crowd we must be on guard against pickpockets, or I'm always on my guard when I'm asked how I voted.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

I loved when a dish caught me off guard.

From Salon • Mar. 17, 2026

But the speed and severity of Iran’s counterattacks across energy powerhouses lining the Persian Gulf caught many off guard.

From The Wall Street Journal • Mar. 7, 2026

"We were taken off guard that it seemed to be working on time scales similar to that of silicon photodetectors."

From Science Daily • Mar. 4, 2026

He said residents were "completely caught off guard" on Sunday morning as news of El Mencho's capture, and the following unrest, broke.

From BBC • Feb. 23, 2026

Elle paused and blinked the way Stephanie usually did when something didn’t compute or when she was caught off guard.

From "Here to Stay" by Sara Farizan

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023