er (from ereb “one, alone”) + cam(b) (“hand”) + ion (#ending for a male name)
Sindarin
erchamion
masculine name. One-handed
erchamion
adjective. one-handed
erchamion
noun. one handed
erchamon
noun. one-handed man
erchammon
noun. one-handed man
erchammui
adjective. one-handed
ergammon
masculine name. One-Handed
erchamion
one-handed
erchamion (pl. erchemyn), also *erchammui, no distinct pl. form. (The word is spelt erchamui in the source.)
erchamion
one-handed
(pl. erchemyn).
erchammon
one-handed man
(pl. erchemmyn). The spelling used in the source is ”erchamon” (VT47:7)
crumui
left-handed
crumui (lenited grumui; no distinct pl. form), also hargam (lenited chargam, pl. hergaim)
crumui
left-handed
(lenited grumui; no distinct pl. form), also hargam (lenited chargam, pl. hergaim).
maenas
handicraft
(i vaenas) (craft, art), pl. maenais (i maenais), coll. pl. maenassath.
Sobriquet of Beren after his hand was bitten off during his quest for a Silmaril (S/183). The two initial elements of this name are er “one” and a mutated form cham of cam “hand” (SA/er, cam). The second of these is especially interesting, in that it is a rare example of liquid mutation. The meaning of the final element is unclear, but it is probably a variant of the masculine suffix -on. As further evidence of this, Tolkien also wrote Erchamon without the i, and according to Patrick Wynne this was clearly deliberate and not a slip (VT47/7, PE21/86).
Conceptual Development: In the earliest Lost Tales from the 1910s, this name appeared as G. Ermabwed (LT2/34). In Silmarillion drafts from the 1930s, this name was revised first to (Ilkorin?) Ermabuin (SM/310), then again to N. Erchamui (LR/146, LR/405). In one place it appeared as Erchamron (Ety/MAP).
As a variation on all these names, the forms N. Er(h)amion or Erchamion appeared as early as the Lays of Beleriand from the 1920s (LB/119, 121) and also in Silmarillion drafts from the 1930s (LR/146, 405). In Lord of the Rings drafts from the 1940s, this name appeared as Erhamion (RS/183) and was firmly established in its final form Erchamion by the time of the Silmarillion revisions from the 1950s-60s (WJ/51, 231).