arrowhead

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The pointed striking tip of an arrow, typically a knapped, wedge-shaped stone or a fitted metal cap.
• noun Something, such as a directional mark on a sign or drawing, having the shape of an arrowhead.
• noun Any of various aquatic or wetland perennial plants of the genus Sagittaria, having arrowhead-shaped leaves and panicles of white, unisexual flowers.
• noun The edible tubers of various Sagittaria species, especially S. sagittifolia of Eurasia or S. latifolia of North America.

from The Century Dictionary.

• noun The pointed member of an egg-and-dart molding; the ‘dart’ or ‘tongue.’ See cut at egg and dart, under egg.
• noun The head of an arrow.
• noun An aquatic plant of the genus Sagittaria: so called from the shape of the leaves. See Sagittaria.
• noun A belemnite.
• Written with arrow-headed characters: as, an arrow-head inscription.

from the GNU version of the Collaborative International Dictionary of English.

• noun the pointed head or striking tip of an arrow.
• noun (Bot.) An aquatic plant of the genus Sagittaria, esp. Sagittaria sagittifolia, -- named from the shape of the leaves.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The pointed part of an arrow (the weapon).
• noun The pointed part of an arrow (the symbol).
• noun Any plant in the genus Sagittaria.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the pointed head or striking tip of an arrow