The Collaborative International Dictionary of English v.0.48:
Headspring \Head"spring`\ (h[e^]d"spr[i^]ng`), n. Fountain; source. [1913 Webster] The headspring of our belief. --Stapleton. [1913 Webster]WordNet (r) 3.0 (2006):
headspring n 1: the source of water from which a stream arises; "they tracked him back toward the head of the stream" [syn: fountainhead, headspring, head]