"This biplane is a first-class machine, warranted in all kinds of weather." "If it am a flyin' machine wot fo' you call it a biplane ?" asked the colored man curiously.
"Bi stands for two," explained Dick.

"A bicycle means two cycles, or two wheels.

A biplane means two planes, or two surfaces of canvas.

This biplane of ours, as you can see, has two surfaces, or decks, an upper and a lower.

A monoplane has only one plane, and a triplane has three.
Now you understand, don't you, Aleck ?" "I dun reckon I do, Massa Dick.