- streamline
- 1868 (n.) "line drawn from point to point, so that its direction is everywhere that of the motion of the fluid" [Lamb, "Hydrodynamics," 1906], from stream + line. The adj. is attested from 1898, "free from turbulence," 1907 in sense of "shaped so that the flow around it is smooth." The verb is attested from 1913 with meaning "give a streamline form to," and 1936 in the extended sense of "simplify and organize."