Eight and one more; one less than ten; as, nine miles. [1913 Webster]

1.  The number greater than eight by a unit; nine units or objects. [1913 Webster]

2.  A symbol representing nine units, as 9 or ix. [1913 Webster]

3.  A group of nine people; as, the New York nine (a baseball team). [PJC]

nine, n. & adj.
--n.
1 one more than eight, or one less than ten; the sum of five units and four units.
2 a symbol for this (9, ix, IX).
3 a size etc. denoted by nine.
4 a set or team of nine individuals.
5 the time of nine o'clock (is it nine yet?).
6 a card with nine pips.
7 (the Nine) the nine muses.
--adj. that amount to nine.

Idiom:
dressed up to the nines dressed very elaborately. nine days' wonder a person or thing that is briefly famous. nine times out of ten nearly always. nine to five a designation of typical office hours.

Etymology:
OE nigon f. Gmc

N  five, five, cinque, quint, quincux, six, half-a- dozen, half dozen, seven, eight, nine, three times three, dicker, ten, decade, eleven, twelve, dozen, thirteen, long dozen, baker's dozen, quintuplet, twenty, score, twenty-four, four and twenty, two dozen, twenty-five, five and twenty, quarter of a hundred, forty, two score, fifty, half a hundred, sixty, three score, seventy, three score and ten, eighty, four score, ninety, fourscore and ten, sestiad, hundred, centenary, hecatomb, century, hundredweight, cwt, one hundred and forty-four, gross, thousand, chiliad, millennium, thousand years, grand, myriad, ten thousand, ban, man, ten thousand years, banzai, lac, one hundred thousand, plum, million, thousand million, milliard, billion, trillion, five, quinary, quintuple, fifth, senary, sextuple, sixth, seventh, septuple, octuple, eighth, ninefold, ninth, tenfold, decimal, denary, decuple, tenth, eleventh, duodenary, duodenal, twelfth, in one's 'teens, thirteenth, vicesimal, vigesimal, twentieth, twenty-fourth, vicenary, vicennial, centuple, centuplicate, centennial, centenary, centurial, secular, hundredth, thousandth.

N  amusement, entertainment, recreation, fun, game, fun and games, diversion, divertissement, reaction, solace, pastime, passetemps, sport, labor of love, pleasure, relaxation, leisure, fun, frolic, merriment, jollity, joviality, jovialness, heyday, laughter, jocosity, jocoseness, drollery, buffoonery, tomfoolery, mummery, pleasantry, wit, quip, quirk, giggle, titter, snigger, snicker, crow, cheer, chuckle, shout, horse laugh, belly laugh, hearty laugh, guffaw, burst of laughter, fit of laughter, shout of laughter, roar of laughter, peal of laughter, cachinnation, Kentish fire, tiger, play, game, game at romps, gambol, romp, prank, antic, rig, lark, spree, skylarking, vagary, monkey trick, gambade, fredaine, escapade, echappee, bout, espieglerie, practical joke, dance, hop, reel, rigadoon, saraband, hornpipe, bolero, ballroom dance, minuet, waltz, polka, fox trot, tango, samba, rhumba, twist, stroll, hustle, cha-cha, fandango, cancan, bayadere, breakdown, cake-walk, cornwallis, break dancing, nautch-girl, shindig, skirtdance, stag dance, Virginia reel, square dance, galop, galopade, jig, Irish jig, fling, strathspey, allemande, gavot, gavotte, tarantella, mazurka, morisco, morris dance, quadrille, country dance, folk dance, cotillon, Sir Roger de Coverley, ballet, ball, bal, bal masque, bal costume, masquerade, Terpsichore, festivity, merrymaking, party, blowout, hullabaloo, hoedown, bat, bum, bust, clambake, donation party, fish fry, jamboree, kantikoy, nautch, randy, squantum, tear, Turnerfest, yule log, fete, festival, gala, ridotto, revels, revelry, reveling, carnival, brawl, saturnalia, high jinks, feast, banquet, regale, symposium, wassail, carouse, carousal, jollification, junket, wake, Irish wake, picnic, fete champetre, regatta, field day, treat, round of pleasures, dissipation, a short life and a merry one, racketing, holiday making, rejoicing, jubilee, bonfire, fireworks, feu-de-joie, firecracker, holiday, gala day, red letter day, play day, high days and holidays, high holiday, Bank holiday, May day, Derby day, Saint Monday, Easter Monday, Whit Monday, Bairam, wayz-goos, bean feast, Arbor Day, Declaration Day, Independence Day, Labor Day, Memorial Day, Thanksgiving Day, Mardi gras, mi-careme, feria, fiesta, place of amusement, theater, hall, concert room, ballroom, assemblyroom, music hall, park, plaisance, national park, national forest, state park, county park, city park, vest-pocket park, public park (public), arbor, garden, pleasure ground, playground, cricketground, croquet ground, archery ground, hunting ground, tennis court, racket court, bowling alley, green alley, croquet lawn, rink, glaciarum, skating rink, roundabout, merry-go-round, swing, montagne Russe, game of chance, game of skill, athletic sports, gymnastics, archery, rifle shooting, tournament, pugilism, sports, horse racing, the turf, aquatics, skating, sliding, cricket, tennis, lawn tennis, hockey, football, baseball, soccer, ice hockey, basketball, rackets, fives, trap bat and ball, battledore and shuttlecock, la grace, pall- mall, tipcat, croquet, golf, curling, pallone, polo, water polo, tent pegging, tilting at the ring, quintain, greasy pole, quoits, horseshoes, discus, rounders, lacrosse, tobogganing, water polo, knurr and spell, leapfrog, hop skip and jump, mother may I, French and English, tug of war, blindman's bluff, hunt the slopper, hide and seek, kiss in the ring, snapdragon, cross questions and crooked answers, crisscross, hopscotch, jacks, jackstones, marbles, mumblety-peg, mumble-the-peg, pushball, shinney, shinny, tag, billiards, pool, pingpong, pyramids, bagatelle, bowls, skittles, ninepins, kain, American bowls, tenpins, tivoli, cards, card games, whist, rubber, round game, loo, cribbage, besique, euchre, drole, ecarte, picquet, allfours, quadrille, omber, reverse, Pope Joan, commit, boston, boaston, blackjack, twenty- one, vingtun, quinze, thirty-one, put, speculation, connections, brag, cassino, lottery, commerce, snip-snap-snoren, lift smoke, blind hookey, Polish bank, Earl of Coventry, Napoleon, patience, pairs, banker, blind poker, draw poker, straight poker, stud poker, bluff, bridge, bridge whist, lotto, monte, three-card monte, nap, penny-ante, poker, reversis, squeezers, old maid, fright, beggar-my- neighbor, baccarat, ace, king, queen, knave, jack, ten, nine, eight, seven, six, five, four, trey, deuce, joker, trump, wild card, spades, hearts, clubs, diamonds, major suit, minor suit, bower, right bower, left bower, dummy, jackpot, deck, pair, two pair, three of a kind, straight, flush, full-house, four of a kind, royal flush, misere chess, draughts, checkers, checquers, backgammon, dominos, merelles, nine men's morris, go bang, solitaire, game of fox and goose, monopoly, loto, scrabble, scribbage, boggle, crossword puzzle, hangman, morra, gambling, toy, plaything, bauble, doll, teetotum, knickknack, magic lantern, peep show, puppet show, raree show, gallanty show, toy shop, quips and cranks and wanton wiles, nods and becks and wreathed smiles, entertainer, showman, showgirl, dancer, tap dancer, song-and-dance man, vaudeville act, singer, musician, sportsman, gamester, reveler, master of ceremonies, master of revels, pompom girl, arbiter elegantiarum, arbiter bibendi, archer, fan, toxophilite, turfman, amusing, entertaining, diverting, recreational, recreative, lusory, pleasant, laughable, witty, fun, festive, festal, jovial, jolly, jocund, roguish, rompish, playful, playful as a kitten, sportive, ludibrious, funny, very funny, hilarious, uproarious, side-splitting, amused, pleased with a rattle, tickled with a straw, laughing, risible, ready to burst, ready to split, ready to die with laughter, convulsed with laughter, rolling in the aisles, on the light fantastic toe, at play, in sport, Int, vive la bagatelle!, vogue la galere!, deus nobis haec otia fecit, dum vivimus vivamus, dulce est desipere in loco, (every room) hath blazed with lights and brayed wi, misce stullitiam consiliis brevem.

be on cloud nine, cat o' nine tails, cloud nine, nine iron, nine times

   tails(n = noun.artifact) dress suit, full dress, tail coat, tailcoat, white tie, white tie and tails - formalwear consisting of full evening dress for men;
is a kind of evening clothes, evening dress, eveningwear, formalwear
has parts: morning coat, swallow-tailed coat, swallowtail

cat o' nine tails, white tie and tails