Plain English Meaning
A fuselage design where the outer shell does the work of holding the aircraft together, instead of relying on an internal skeleton of beams and braces.
Full Definition
A type of aircraft fuselage construction in which the outer skin carries most or all of the structural loads, with little or no internal framework. The shape and strength of the structure come from the stressed skin itself, often supported only by formers and bulkheads that give the fuselage its cross-sectional shape.
Context Anchor
Seen in airframe and fuselage construction discussions, especially when comparing older shell-type designs with semi-monocoque construction.
Derivation
From the French mono- (single) and coque (shell). The idea is a 'single shell' that is strong enough on its own to carry the loads, the way an eggshell holds its shape without anything inside it.