Meaning of the word smarten-up in English

What does smarten-up mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

smarten-up

US /ˈsmɑːr.tən/
UK /ˈsmɑː.tən/

to (cause to) become more clean, neat, and stylish:

Example:
She's really smartened herself up since she finished college.