Definition
An electric lamp that produces light by passing current through a thin filament, usually tungsten, sealed inside a glass envelope filled with an inert gas or held under vacuum. The filament becomes white-hot from electrical resistance and gives off visible light along with a large amount of heat.
Plain English
A light bulb that works by heating a tiny wire inside until it glows. Electricity flows through the wire, the wire gets extremely hot, and the heat makes it shine.
Context Anchor
Seen in aircraft lighting discussions, including older instrument lights, panel lights, cabin lights, landing lights, and position lights.
Derivation
From the Latin 'incandescere,' meaning 'to glow white' or 'to become hot.' The name describes exactly how the lamp works: it produces light by glowing white-hot, not by any chemical or electronic process.
Why Pilots Care
Provides reliable illumination in legacy aircraft systems, though modern aircraft increasingly use LED alternatives for lower power and longer life.
Intuition Check
Do not read “lamp” here as the whole light fixture. In this context, an incandescent lamp is the bulb or light source that glows because a wire inside is heated.
Example Sentence 1
The pilot replaced a burned-out incandescent lamp in the panel lighting circuit before the night cross-country flight.
Example Sentence 2
During preflight, check that all incandescent lamps in the exterior lighting system illuminate properly.