"raise or arouse, stir up" (from one's bed, etc.), 1650s, probably an alteration of rouse with excrescent -t. Related: Rousted; rousting.
Entries linking to roust
mid-15c., rousen, intransitive, probably from Anglo-French or Old French reuser, ruser; Middle English Compendium compares 16c. French rousee "abrupt movement." Sometimes also said to be from Latin recusare "refuse, decline," with loss of the medial -c-. Originally in English a technical term in hawking, "to shaking the feathers of the body," but like many medieval hawking and hunting terms it is of obscure origin.
The sense of "cause game to rise from cover or lair" is from 1520s. The word became general from 16c. in the figurative, transitive, meaning "stir up, cause to start up by noise or clamor, provoke to activity; waken from torpor or inaction" (1580s); that of "to awaken, cause to start from slumber or repose" is recorded by 1590s. Related: Roused; rousing.
"common deck hand, wharf worker," 1868, American English, perhaps from roust + about. But another theory connects it to British dialect rousing "rough, shaggy," a word associated perhaps with rooster. Meanwhile, compare rouseabout "a restless, roaming person" (1746), which seems to have endured in Australian and New Zealand English. With extended senses in U.S., including "circus hand" (1931); "manual laborer on an oil rig" (1948).