What does plane mean?
A plane is a flat, level surface, but in everyday use the word most often refers to an aircraft. It can also mean an ideal flat surface extending without limit in geometry, or a flat area considered as a distinct level within a larger space. As a verb, to plane means to move smoothly along or just above a surface, as a bird might do, or to shave and smooth wood with a tool. The word is therefore useful across ordinary, technical, and figurative contexts. “Plane” sounds less formal than “aircraft” when describing a flying vehicle, while in mathematics it is a precise geometric term. In woodworking, the same word names both the surface being smoothed and the tool used to smooth it. Its range of meanings connects the flatness of a surface with the graceful, level movement of a plane through the sky.
A flat, level surface, especially one regarded as extending infinitely in all directions in geometry; also an aircraft.
"The plane was delayed by fog at the airport."
To skim or glide smoothly over a surface, or to cut or smooth something with a plane.
"The seagull planed over the waves before landing on the pier."
Flat, level, or having no curvature or irregularities.
"The wall has a plane surface that reflects the sunlight evenly."
Plural “planes” can refer to multiple aircraft, geometric planes, or flat surfaces, depending on context.
"Several planes circled above the airport while they waited for clearance."
A single word can move from a carpenter’s flat surface to the sky: a plane is both a tool for smoothing wood and a vehicle that sails through the air.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Words that share this root
Related word forms
How plane is actually used
When referring to an aircraft, “plane” is informal but universally understood; “aircraft” is the more formal and technically precise term. In geometry, “plane” is a noun, while “planar” is the corresponding adjective. As a verb, it can suggest smooth, low movement over a surface and is often used in descriptions of birds, aircraft, or boats.