Plain English Meaning
How easy something is to see and notice. A high-conspicuity light or marking grabs your eye quickly, even when conditions make it hard to see other things.
Full Definition
The quality of being clearly visible and easily noticed against the surrounding environment. In airport operations, conspicuity refers to how readily a marking, light, sign, or vehicle stands out to pilots and controllers, particularly in conditions that reduce visibility such as night, rain, or low sun angles.
Context Anchor
Seen in airport lighting discussions, especially runway guard lights, which are designed to make runway entrance areas more noticeable.
Derivation
From the Latin conspicere, meaning 'to look at' or 'catch sight of' (con- 'thoroughly' + specere 'to look'). The is the same as in 'spectacle' and 'inspect.' Knowing this helps: conspicuity is literally about how strongly something catches the eye.