to make more trim or spruce; improve in appearance (usually fol. by up )

Try to smarten up your outfit.

to make brisker, as a pace.

to sharpen the judgment or broaden the experience of; educate (usually fol. by up )

Someone has to smarten him up about dealing with people.

smarten up,

to groom oneself

to smarten up before dinner.

to become aware of one's mistakes, shortcomings, etc., and make efforts to correct them

If you don't smarten up, you're going to be out of a job.

verb

fix up , spruce