1580s, noun ("person who acts madly or wildly") and adjective ("wild, harum-scarum), from mad (adj.) + cap, used here figuratively for "head." Related: Madcappery. Compare mad-brain "rash or hot-headed person" (1560s).

early 14c., "attempt, attack," (in phrase make a fling), from fling (v.). Hence have a fling at, etc. "make a try." From 1560s as "a wild dash, an excited kicking up." Sense of "period of indulgence on the eve of responsibilities" first attested 1827. Meaning "vigorous dance" (associated with the Scottish Highlands) is from 1804.

also woolly, 1570s, "resembling or made of wool," from wool + -y (2). Meaning "barbarous, rude" is recorded 1891, from wild and wooly (1884) applied to the U.S. western frontier, perhaps in reference to range steers or to unkempt cowboys. Related: Wooliness.

ancient region southeast of the Caspian Sea, from Greek Hyrkania, said to be from an Indo-European *verkana "country of wolves" [Zonn, I., et al., "The Caspian Sea Encyclopedia," 2010]. "Hyrcania was the wild region par excellence to the ancients" [OED]. Related: Hyrcanian.

1733, "horse-breaker, one who breaks young or wild horses for the saddle;" see rough (adj.) + rider. Of horses, rough (adj.) meaning "not properly broken in" is from 1590s. The meaning "irregular cavalryman" is attested by 1884. Related: Rough-riding.

undomesticated cat, early 14c. (late 12c. as a surname), from wild (adj.) + cat (n.). Meaning "savage woman" is recorded from 1570s; sense of "one who forms rash projects" is attested from 1812. The adjective in the financial speculative sense is first recorded 1838, American English.

c. 1600, "that howls," present-participle adjective from howl (v.)). The word was used in the King James Bible (1611) in reference to waste and wilderness (Deuteronomy xxxii.10), "characterized by or filled with howls (of wild beasts or the wind," which has tended to give it a merely intensive force.

Old English hwelp "whelp, young of the dog," from a Germanic root related to Old Saxon hwelp, Old Norse hvelpr, Dutch welp, German hwelf; of unknown origin. Now largely displaced by puppy. Also applied to wild animals. Sense of "scamp" first recorded early 14c.

"cat-like," 1680s, from Late Latin felinus "of or belonging to a cat," from Latin feles (genitive felis) "cat, wild cat, marten," which is of uncertain origin. Hence Modern Latin Felis, the cat genus. As a noun, "a feline animal" (popularly "a domestic cat") from 1861.

form of Greek choric composition, c. 1600, from Latin dithyrambus, from Greek dithyrambos, which is of unknown origin, perhaps a pre-Hellenic loan-word. A wild choric hymn, originally in honor of Dionysus or Bacchus, later of other gods, heroes, etc. Related: Dithyrambic.