Name
The English word elf is from the Old English ælf or elf; in compound as ælfadl "nightmare," ælfsogoða "hiccup," afflictions apparently thought to be caused by elves.
The Old English word is derived from the Proto-Germanic *albiz, which also resulted in Old Norse álfr and Middle High German elbe. *Albiz may be from the Proto-Indo-European root *albh- meaning "white", from which also stems the Latin albus "white". Alternatively, a connection to the Rbhus, semi-divine craftsmen in Indian mythology, has also been suggested(OED).
Originally ælf/elf and its plural ælfe were the masculine forms, while the corresponding feminine form (first found in eighth century glosses) was ælfen or elfen (with a possible feminine plural -ælfa, found in dunælfa) which became the Middle English elven, using the feminine suffix -en from the earlier -inn which derives from the Proto-Germanic *-innja). The fact that cognates exist (such as the German elbinne) could suggest a West Germanic *alb(i)innjo, but this is uncertain, as the examples may be simply a transference to the weak declension common in Southern and Western forms of Middle English. The Middle English forms with this weak declension were aluen(e) and eluen(e). By the earlier eleventh century ælf could denote a female.
The Modern German Elf (m), Elfe (f), Elfen is a loan from English. A masculine Elb is reconstructed from the plural by Jacob Grimm, Deutsches Wörterbuch, who rejects Elfe as a (then, in the 1830s) recent anglicism. Elb (m, plural Elbe or Elben) is a reconstructed term, while Elbe (f) is attested in Middle High German. Alb, Alp (m), plural Alpe has the meaning of "incubus" (Old High German alp, plural *alpî or *elpî). Gothic has no direct testimony of *albs, plural *albeis, but Procopius has the personal name Albila.
http://en.wikipedia.org/wiki/Elf
http://marl.egloos.com/3196688
