Windchill is how much colder moving air makes the temperature feel on bare skin. The windchill factor, allow for windchill, a windchill of minus ten.
The thermometer does not move at all, since windchill measures the rate at which wind strips the warm layer of air off your skin. It matters only to things that make their own heat, so a parked car never cools below the real temperature however hard the wind blows.
1nounwindchillHow much colder moving air makes it feel.
“It was minus two, but the windchill made it feel like minus twelve.”
windchill is a measure.
wind chill comes from wind + chill.
Etymology from Wiktionary, CC BY-SA
Practised in Weather & Seasons