Definition of altimeter in US English:


(also alt.)


  • An instrument for determining altitude attained, especially a barometric or radar device used in an aircraft.

    • ‘On entering the water, I am immediately on an undersea treadmill, legs pumping furiously, pressure gauge falling like the altimeter of a crashing aircraft.’
    • ‘Our wingman called ‘lost sight’ and reported that his radar altimeter, which had been intermittent, had decided to fail entirely.’
    • ‘The Dorset-based firm produces devices such as altimeters, braking systems, smoke detectors and towed aerial targets that act as decoys for enemy fire.’
    • ‘They had not yet gotten used to flying blacked out over shifting sand dunes and having their attention refocused every time the radar altimeter indicated less than 10 feet above the ground.’
    • ‘At a height of 60 kilometres, it will be able to detect its own altitude using a pair of radar altimeters, which will be able to measure the exact distance to the surface.’


Early 20th century: from Latin altus ‘high’ + -meter.