he·lio·met·ric \|hēlēō|me.trik\adjective Etymology: French héliométrique, from hélio- heli- (I) + -métrique -metric : of, employing, or obtained by use of a heliometer < heliometric observations > < heliometric results > • he·lio·met·ri·cal·ly\-rə̇k(ə)lē\adverb