the world > action or operation > manner of action > vigour or energy > act or do vigorously [verb (intransitive)] > be brisk or active > become brisk or active (2)
intransitive. To become brisk, to speed up.
intransitive (for reflexive). to brisk about: to move about briskly. to brisk up: to come up briskly; to become brisk, to behave or move in a brisk…