To attack from behind or when out of earshot with spiteful or defamatory remarks.
To speak badly of an absent individual.
To make spiteful slanderous or defamatory statements about someone.
One who engages in backbiting; a backbiter.
To become optimal.
To act optimistically or as an optimist.
To make (something) more efficient, such as a computer program.
To make (something) optimal.