fiend

O.E. feond "enemy, foe," originally prp. of feogan "to hate," from P.Gmc. *fijæjan (cf. O.Fris. fiand "enemy," O.S. fiond, M.D. viant, Du. vijand "enemy," O.N. fjandi, O.H.G. fiant, Goth. fijands), from PIE base *pe(i)- "to blame, revile" (cf. Goth. faian "to blame;" see passion). As spelling suggests, it was originally the opposite of friend, but the word began to be used in O.E. for "Satan" (as the "enemy of mankind"), which shifted its sense to "diabolical person" (early 13c.). The old sense of the word devolved to foe, then to the imported word enemy. For spelling with -ie- see field. Meaning "devotee (of whatever is indicated)," e.g. dope fiend, is from 1865.

enemy

early 13c., from O.Fr. enemi (12c.), earlier inimi (9c.) "enemy, adversary, foe, demon, the Devil," from L. inimicus "hostile, unfriendly; an enemy" (cf. It. nemico, Cat. enamic, Sp. enemigo, Port. inimigo), from in- "not" (see in- (1)) + amicus "friend" related to amare "to love" (see Amy). Most words for "personal enemy" cover also "enemy in war," but certain languages have special terms for the latter, e.g. Gk. polemioi (distinct from ekhthroi), L. hostis, originally "stranger" (distinct from inimicus), Rus. neprijatel' (distinct from vrag). Rus. vrag (O.C.S. vragu) is cognate with Lith. vargas "misery" (see urge), and probably is related to P.Gmc. *wargoz, source of O.N. vargr "outlaw," hence "wolf;" Icel. vargur "fox," O.E. wearg "criminal, felon;" which likely were the inspirations for J.R.R. Tolkien's warg "a kind of large ferocious wolf" in "The Hobbit" (1937) and "Lord of the Rings." Related: Enemies.

foe

O.E. gefa "foe, enemy, adversary in a blood feud" (the prefix denotes "mutuality"), from fah "at feud, hostile," from P.Gmc. *fakhaz (cf. O.H.G. fehan "to hate," Goth. faih "deception"), probably from PIE base *peig- "evil-minded, treacherous, hostile" (cf. Skt. pisunah "malicious," picacah "demon;" Gk. pikros "bitter;" Lith. piktas "wicked, angry," pekti "to blame"). Weaker sense of "adversary" is first recorded c.1600.

O.E. gæst, giest (Anglian gest) "guest, enemy," the common notion being "stranger," from P.Gmc. *gastiz (cf. O.Fris. jest, Du. gast, Ger. Gast, Goth. gasts), from PIE base *ghostis "strange" (cf. L. hostis "enemy," hospes "host" -- from *hosti-potis "host, guest," originally "lord of strangers" -- Gk. xenos "guest, host, stranger;" O.C.S. gosti "guest, friend," gospodi "lord, master"). Spelling evolution influenced by O.N. cognate gestr (the usual sound changes from the O.E. word would have yielded Mod.Eng. *yest). Phrase be my guest in the sense of "go right ahead" first recorded 1955.

host (1)

"person who receives guests," late 13c., from O.Fr. hoste "guest, host" (12c.), from L. hospitem (nom. hospes) "guest, host," lit. "lord of strangers," from PIE *ghostis- "stranger" (cf. O.C.S. gosti "guest, friend," gospodi "lord, master;" see guest). The biological sense of "animal or plant having a parasite" is from 1857. The verb is early 15c., from the noun. Related: Hosted; hosting.

仇

仇：      「かたき」『詩経・大雅』『鄭箋』。「仇敵」「仇讐」（『左伝』）（『字統』）

敵：      ?は帝を祀るもの、帝の嫡系を示す。匹敵するの意味をもつ。対等・同等（『字統』）。

讐：     上部は当事者の双方から貲として提出した鳥（隹）。言は神に誓約して違背するときは自ら罰を受けるとする自己詛盟。即ち訟獄のことを争う意（『字統』）。