The Collaborative International Dictionary of English v.0.48:
Altimeter \Al*tim"e*ter\, n. [LL. altimeter; altus high + metrum, Gr. ?, measure: cf. F. altim[`e]tre.] An instrument for taking altitudes, as a quadrant, sextant, etc. --Knight. [1913 Webster]WordNet (r) 3.0 (2006):
altimeter n 1: an instrument that measures the height above ground; used in navigation