motion sensor
noun
A sensor that is sensitive to motion; a motion detector, especially as (part of) a security device that can trigger a burglar alarm, or as an aid to positioning or navigation.
Origin
1960s; earliest use found in Science.
- groundmass
- groundnut
- groundnut oil
- groundout
- ground pine
- ground plan
- ground rent
- ground rule
- ground run
- groundsel
- groundshare
- groundsheet
- groundsill
- groundskeeper
- ground sloth
- groundsman
- ground speed
- ground squirrel
- ground staff
- ground state
- groundstroke
- groundswell
- ground tackle
- ground-to-air
- ground troops