Decrease of workforce caused by non-replacement of retiring or voluntarily resigning employees and not by deliberate layoffs.
The amount of avoidable loss that results from choosing the wrong action.
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.
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).