The Collaborative International Dictionary
Hecdecane
Hecdecane \Hec"de*cane\, n. [Gr. ? six + ? ten.] (Chem.) A white, semisolid, spermaceti-like hydrocarbon, C16H34, of the paraffin series, found dissolved as an important ingredient of kerosene, and so called because each molecule has sixteen atoms of carbon; -- called also hexadecane.
Wiktionary
hecdecane
n. (archaic form of hexadecane English)