mid-15c., intransitive probably from Anglo-French or Old French reuser, ruser, originally used in English of hawks shaking the feathers of the body, but like many hawking terms it is of obscure origin. Figurative meaning "to stir up, provoke to activity" is from 1580s; that of "awaken" is first recorded 1590s. Related: Roused; rousing.
He was roused by the drunken men in the street
Roundhead
roundhouse
roundness
round-table
roundup
rouse
rouser
roust
roustabout
rout
route