To express regret that a certain event has occurred.
To make an apology or excuse; to acknowledge some fault or offense, with expression of regret for it, by way of amends
To feel sorry about (a thing that has or has not happened), afterthink: to wish that a thing had not happened, that something else had happened instead.
To feel sorry about (any thing).
Emotional pain on account of something done or experienced in the past, with a wish that it had been different; a looking back with dissatisfaction or with longing.
The amount of avoidable loss that results from choosing the wrong action.