The Quenya word for “five” derived from the root √LEPEN via the Quenya syncope and metathesis: ✶lepene > lepne > lenpe > lempe (PE17/95; VT42/24; VT47/10; VT48/6; Ety/LEP).
Conceptual Development: The Qenya Lexicon of the 1910s had ᴱQ. lemin “five” under the early root ᴱ√LEH [LEǶE] “half”, and Q. lempe was “ten” in this 1910s document (QL/52). In the contemporaneous Gnomish Lexicon, the word lempe was “five” (GL/53). In the Early Qenya Grammar of the 1920s (EQG), lemin “five” reappeared and ᴱQ. lempe was “half” (PE14/49, 82, 84). Beginning with The Etymologies of the 1930s the usual Quenya word for “five” was lempe (Ety/LEP), but occasional variants like lemne and lemen continued to appear (PE17/95; VT48/6).
A neologism from the NQW for “volt”, a loan word.