/al tim"i teuhr, al"teuh mee'teuhr/ , n.
1. a sensitive aneroid barometer that is graduated and calibrated, used chiefly in aircraft for finding distance above sea level, terrain, or some other reference point by a comparison of air pressures.
2. any device used for the same purpose that operates by some other means, as by radio waves.
[ 1820-30; ALTI- + -METER ]