Plain English Meaning

A line that runs through the middle of the wing from front to back, staying equally far from the top and bottom surfaces the whole way. The more this line curves, the more curved the wing is overall.

Full Definition

An imaginary line drawn from the leading edge to the trailing edge of an airfoil, positioned exactly halfway between the upper and lower surfaces at every point along the chord. The shape and curvature of this line define the airfoil's camber — the amount and distribution of curve built into the wing.

Context Anchor

Seen in wing and airfoil diagrams when learning how wing shape affects lift.

Derivation

‘Mean’ here comes from the Latin ‘medianus’ meaning ‘middle’ — it’s the same ‘mean’ used in mathematics for an average. ‘Camber’ comes from Old French ‘cambre’ meaning ‘curved’ or ‘arched.’ So a mean camber line is literally the ‘middle curve line’ of the wing.