Old English wulf "wolf, wolfish person, devil," from Proto-Germanic *wulfaz (source also of Old Saxon wulf, Old Norse ulfr, Old Frisian, Dutch, Old High German, German wolf, Gothic wulfs), from PIE root *wlkwo- "wolf" (source also of Sanskrit vrkas, Avestan vehrka-; Albanian ul'k; Old Church Slavonic vluku; Russian volcica; Lithuanian vilkas "wolf;" Old Persian Varkana- "Hyrcania," district southeast of the Caspian Sea, literally "wolf-land;" probably also Greek lykos, Latin lupus).
This manne can litle skyl ... to saue himself harmlesse from the perilous accidentes of this world, keping ye wulf from the doore (as they cal it). ["The Institution of a Gentleman," 1555]
Probably extinct in England from the end of the 15th century; in Scotland from the early 18th. Wolves as a symbol of lust are ancient, such as Roman slang lupa "whore," literally "she-wolf" (preserved in Spanish loba, Italian lupa, French louve). The equation of "wolf" and "prostitute, sexually voracious female" persisted into 12c., but by Elizabethan times wolves had become primarily symbolic of male lust. The specific use of wolf for "sexually aggressive male" first recorded 1847; wolf-whistle attested by 1945, American English, at first associated with sailors. The image of a wolf in sheep's skin is attested from c. 1400. See here for a discussion of "wolf" in Indo-European history. The wolf-spider so called for prowling and leaping on its prey rather than waiting in a web.
"of a color between white and black; having little or no color or luminosity," Old English græg "gray" (Mercian grei), from Proto-Germanic *grewa- "gray" (source also of Old Norse grar, Old Frisian gre, Middle Dutch gra, Dutch graw, Old High German grao, German grau), with no certain connections outside Germanic. French gris, Spanish gris, Italian grigio, Medieval Latin griseus are Germanic loan-words. The spelling distinction between British grey and U.S. gray developed 20c. Expression the gray mare is the better horse in reference to households ruled by wives is recorded from 1540s.
c. 1200, from gray (adj.). Gray as figurative for "Southern troops in the U.S. Civil War" is first recorded 1863, in reference to their uniform color.
"become gray, wither," 1610s (with an isolated instance from late 14c.), from gray (adj.). Related: Grayed; graying.
large gray wolf of the U.S. southwest, 1859, from Spanish lobo "a wolf," from Latin lupus (see wolf (n.)).
"wolf-like," 1650s, from French lupin "wolf-like; vicious, ferocious," from Latin lupinus "of the wolf" (source also of Spanish and Italian lupino), from lupus "wolf" (see wolf (n.)).
masc. proper name, from German Rudolf, from Old High German Hrodulf, literally "fame-wolf," from hruod- "fame, glory" (from Proto-Germanic *hrothi-) + wolf (see wolf (n.)).