second thought

Từ điển WordNet v3.1 - WordNet Dictionary

noun

thinking again about a choice previously made (Freq. 1)
- he had second thoughts about his purchase
• Syn:
reconsideration, afterthought, rethink
• Derivationally related forms:
rethink (for: rethink), reconsider (for: reconsideration)
• Hypernyms:
reversal, change of mind, flip-flop, turnabout, turnaround