ar·row·head 
(ărō-hĕd′)
(ărō-hĕd′)n.
1. The pointed striking tip of an arrow, typically a knapped, wedge-shaped stone or a fitted metal cap.
2. Something, such as a directional mark on a sign or drawing, having the shape of an arrowhead.
3.
a. Any of various aquatic or wetland perennial plants of the genus Sagittaria, having arrowhead-shaped leaves and panicles of white, unisexual flowers.
b. The edible tubers of various Sagittaria species, especially S. sagittifolia of Eurasia or S. latifolia of North America.