One who moves or goes about briskly and constantly; see trot, v. 2.

A person or animal that moves briskly; one who bestirs himself, an active person. †Of a horse: see stirring, n. 3b, stirring, adj. 2b.

figurative, typically connoting activeness or the performance of an action.

U.S. One who ‘shins round’; an active person.

One who is continually ‘staving’ about; an active, energetic person.

A formidable, extraordinary, or troublesome person.