Regret/rɪˈɡret/ Definition 1 of 3Pro Tip 1/3Past Actions Used when reflecting on actions you've done that you wish you hadn't. I regret yelling at you yesterday. Pro Tip 2/3Missed Opportunities Use it to talk about lost chances or things you didn't do but wish you had. I regret not learning to play the piano. Pro Tip 3/3Emphasize Feelings Often used to emphasize personal responsibility and guilt about the past. He regretted his harsh words bitterly.