second thought

Or second-thought

noun

1. Often second thoughts. reservation about a previous action, position, decision, judgment, or the like.

   He had second thoughts about his decision.

second thought

noun

1. (usually plural) a revised opinion or idea on a matter already considered

Word History and Origins

Origin of second thought¹

First recorded in 1625–35

Idioms and Phrases

Idioms

1. on second thought, after reconsideration.

   On second thought, I don't think I'll go.