set about

US /set əˈbaʊt/
UK /set əˈbaʊt/
"set about" picture
1.

to start doing something, especially something that requires a lot of effort or planning

:
We need to set about finding a solution to this problem immediately.
She set about organizing her new office.
2.

to attack someone or something

:
The dog suddenly set about the mailman.
He was set about by a group of thugs.