gnomon

English Thesaurus

1. indicator provided by the stationary arm whose shadow indicates the time on the sundial (noun.artifact)

hypernym	:	indicator,
definition	:	a device for showing the operating condition of some system (noun.artifact)

part meronym	:	sundial,
definition	:	timepiece that indicates the daylight hours by the shadow that the gnomon casts on a calibrated dial (noun.artifact)