roustabout

As a noun roustabout

is (chiefly|us) an unskilled laborer, especially at an oilfield, at a circus or on a ship.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between roustabout and stevedore

is that roustabout is an unskilled laborer, especially at an oilfield, at a circus or on a ship while stevedore is a dockworker involved in loading and unloading cargo.

As a verb stevedore is

to load or unload a ship's cargo.

As nouns the difference between landman and roustabout

is that landman is someone who lives or works on land, as opposed to a seaman while roustabout is (chiefly|us) an unskilled laborer, especially at an oilfield, at a circus or on a ship.

As nouns the difference between roustabout and swamper

is that roustabout is (chiefly|us) an unskilled laborer, especially at an oilfield, at a circus or on a ship while swamper is (us) a person who lives in a swampy area.