The Collaborative International Dictionary of English v.0.48:

Clinometer \Cli*nom"e*ter\, n. [Gr. kli`nein to incline +
   -meter.] (Geol.)
   An instrument for determining the dip of beds or strata, pr
   the slope of an embankment or cutting; a kind of plumb level.
   --Dana.
   [1913 Webster]

WordNet (r) 3.0 (2006):

clinometer
    n 1: an instrument used by surveyors in order to measure an
         angle of inclination or elevation [syn: clinometer,
         inclinometer]