gnomon是什么意思

gnomon

英 ['nəʊmɒn] 美 ['nomɑn]

gnomon (n.): "vertical shaft that tells time by the shadow it casts" (especially the triangular plate on a sundial), 1540s, from Latin gnomon, from Greek gnomon "indicator (of a sundial), carpenter's rule," also, in plural, "the teeth that mark the age of a horse or mule," literally "one that discerns or examines," from gignoskein "to come to know" (see gnostic (adj.)). In geometry from 1560s, from a use in Greek. In early use in English sometimes folk-etymologized as knowman. Related: Gnomonic.

2. The gnomon - and - ruler indicates the time by the length of the shadow of stylus in the sun.: 圭表是利用太阳射影的长短来判断时间的.