1. Second person singular past tense of 'can'; archaic form meaning 'were able to' or 'could'.
Usage: archaic; used in Early Modern English and biblical/literary contexts; second person singular form, typically with 'thou'

Examples

• Thou couldst have prevented this tragedy.
• If thou couldst see what I see, thou wouldst understand.
• Couldst thou forgive me for my transgression?
• He asked if she couldst speak the ancient language.
• Thou couldst not have known the truth at that time.