[Edward Manning Ruttenber (1906)] Watchung (Wacht-unk, Del.) is from _Wachtschu_ (Zeisb.), "Hill or mountain," and _-unk,_ locative, "at" or "on." _Wachtsûnk,_ "On the mountain" (Zeisb.); otherwise written _Wakhunk._ The original application was to a hill some twelve miles west of the Hudson. The first deed (1667) placed the boundmark of the tract "At the foot of the great mountain," and the second deed (1677) extended the limit "To the top of the mountain called Watchung." Achkinckeshacky; _Hackinkeshacky,_ 1645; _Hackinghsackin, Hackinkesack_ (1660); _Hackensack_ (1685); _Ackinsack, Hockquindachque; Hackquinsack,_ are early record forms of the name of primary application to the stream now known as the Hackensack, from which it was extended to the adjacent district, to an Indian settlement, and to an Indian sachem, or, as Van Tienhoven wrote, "A certain savage chief, named Haickquinsacq." (Breeden Raedt.) The most satisfactory interpretation of the name is that suggested by the late Dr. Trumbull: "From _Huckquan,_ Mass., _Hócquaan,_ Len., 'Hook,' and _sauk,_ 'mouth of a river'--literally, 'Hook-shaped mouth,' descriptive of the course of the stream around Bergen Point, by the Kil van Kull, [FN-1] to New York Bay." Campanus wrote _Hócküng,_ "Hook," and Zeisberger, _Hócquaan._ [FN-2] The German _Hacken,_ now Hackensack, means "Hook," as in German _Russel Hacken,_ "Pot-hook," a hook incurved at both ends, as the letter S; in Lenape _Hócquoan_ (Zeisb.). Probably simply a substitution.