boundary layer

noun

: a region of fluid (such as air) moving relative to a nearby surface (such as that of an airplane wing) that is slowed by the viscosity of the fluid and its adhesion to the surface

Examples of boundary layer in a Sentence

Recent Examples on the Web

This configuration exploits the boundary layer of air flowing over the airframe to increase efficiency. —David Szondy june 14, New Atlas, 14 June 2026

This boundary layer has two states: laminar flow, in which air flows in an orderly fashion, and turbulent flow, which involves turbulence. —Ritsuko Kawai, Wired News, 24 May 2026

And smoothness matters because the thin boundary layer of air clinging to the ball determines where the flow separates, how large a wake forms, and how much drag the ball experiences. —John Eric Goff, The Conversation, 13 May 2026

In the dual frame construction, a boundary layer dividing the carbon fiber helps make the frame compression more resilient. —Tim Newcomb, Forbes.com, 1 Apr. 2026

Word History

First Known Use

1921, in the meaning defined above

Rhymes for boundary layer

• assayer
• ballplayer
• betrayer
• bilayer
• bricklayer
• conveyer
• conveyor
• purveyor
• ratepayer
• soothsayer
• surveyor
• taxpayer