1
general::
1. Apply oneself, begin, work energetically, as in We set to revamping our policy on child care, or She set to studying for the bar exam. [Early 1400s] 2. Begin fighting, as in Both of them were furious, and they set to immediately. [First half of 1700s]
American Heritage Idioms
2
general::
Phrase(s): *set to do something
ready to do something. (*Typically: be ~; get ~.) • I’m all set to go. Are you ready? • We are set to leave at a moment’s notice., Phrase(s): set to
to begin to fight; to attack or commence someone or something. • The two boys set to almost as soon as they met each other. • They set to and fought for about ten minutes, cursing and screaming.
McGrawhill's American Idioms And Phrasal Verbs