petticoat(n = noun.artifact) half-slip, underskirt - undergarment worn under a skirt;
is a kind of undergarment, unmentionable
has particulars: crinoline

   A loose under-garment worn by women, and covering the body below the waist. [1913 Webster]

petticoat, n.
1 a woman's or girl's skirted undergarment hanging from the waist or shoulders.
2 sl. a a woman or girl. b (in pl.) the female sex.
3 (attrib.) often derog. feminine; associated with women (petticoat pedantry).

Derivative:
petticoated adj. petticoatless adj.

Etymology:
ME f. petty coat

N  clothing, investment, covering, dress, raiment, drapery, costume, attire, guise, toilet, toilette, trim, habiliment, vesture, vestment, garment, garb, palliament, apparel, wardrobe, wearing apparel, clothes, things, underclothes, array, tailoring, millinery, finery, full dress, garniture, theatrical properties, outfit, equipment, trousseau, uniform, regimentals, continentals, canonicals, livery, gear, harness, turn-out, accouterment, caparison, suit, rigging, trappings, traps, slops, togs, toggery, day wear, night wear, zoot suit, designer clothes, masquerade, dishabille, morning dress, undress, kimono, lungi, shooting-coat, mufti, rags, tatters, old clothes, mourning, weeds, duds, slippers, robe, tunic, paletot, habit, gown, coat, frock, blouse, toga, smock frock, claw coat, hammer coat, Prince Albert coat, sack coat, tuxedo coat, frock coat, dress coat, tail coat, cloak, pall, mantle, mantlet mantua, shawl, pelisse, wrapper, veil, cape, tippet, kirtle, plaid, muffler, comforter, haik, huke, chlamys, mantilla, tabard, housing, horse cloth, burnoose, burnous, roquelaure, houppelande, surcoat, overcoat, great coat, surtout, spencer, mackintosh, waterproof, raincoat, ulster, P-coat, dreadnought, wraprascal, poncho, cardinal, pelerine, barbe, chudder, jubbah, oilskins, pajamas, pilot jacket, talma jacket, vest, jerkin, waistcoat, doublet, camisole, gabardine, farthingale, kilt, jupe, crinoline, bustle, panier, skirt, apron, pinafore, bloomer, bloomers, chaqueta, songtag, tablier, pants, trousers, trowsers, breeches, pantaloons, inexpressibles, overalls, smalls, small clothes, shintiyan, shorts, jockey shorts, boxer shorts, tights, drawers, panties, unmentionables, knickers, knickerbockers, philibeg, fillibeg, pants suit, culottes, jeans, blue jeans, dungarees, denims, Levis, Calvin Klein, Calvins, Bonjour, Gloria Vanderbilt, headdress, headgear, chapeau, crush hat, opera hat, kaffiyeh, sombrero, jam, tam-o-shanter, tarboosh, topi, sola topi, pagri, puggaree, cap, hat, beaver hat, coonskin cap, castor, bonnet, tile, wideawake, billycock, wimple, nightcap, mobcap, skullcap, hood, coif, capote, calash, kerchief, snood, babushka, head, coiffure, crown, chignon, pelt, wig, front, peruke, periwig, caftan, turban, fez, shako, csako, busby, kepi, forage cap, bearskin, baseball cap, fishing hat, helmet, mask, domino, body clothes, linen, hickory shirt, shirt, sark, smock, shift, chemise, night gown, negligee, dressing gown, night shirt, bedgown, sac de nuit, underclothes, underpants, undershirt, slip, brassiere, corset, stays, corsage, corset, corselet, bodice, girdle, stomacher, petticoat, panties, under waistcoat, jock, athletic supporter, jockstrap, sweater, jersey, cardigan, turtleneck, pullover, sweater vest, neckerchief, neckcloth, tie, ruff, collar, cravat, stock, handkerchief, scarf, bib, tucker, boa, cummerbund, rumal, rabat, shoe, pump, boot, slipper, sandal, galoche, galoshes, patten, clog, sneakers, running shoes, hiking boots, high-low, Blucher boot, wellington boot, Hessian boot, jack boot, top boot, Balmoral, arctics, bootee, bootikin, brogan, chaparajos, chavar, chivarras, chivarros, gums, larrigan, rubbers, showshoe, stogy, veldtschoen, legging, buskin, greave, galligaskin, gamache, gamashes, moccasin, gambado, gaiter, spatterdash, brogue, antigropelos, stocking, hose, gaskins, trunk hose, sock, hosiery, glove, gauntlet, mitten, cuff, wristband, sleeve, swaddling cloth, baby linen, layette, ice wool, taffeta, pocket handkerchief, hanky, hankie, clothier, tailor, milliner, costumier, sempstress, snip, dressmaker, habitmaker, breechesmaker, shoemaker, Crispin, friseur, cordwainer, cobbler, hosier, hatter, draper, linen draper, haberdasher, mercer, diaper, nappy, disposable diaper, cloth diaper, Luvs Huggies, invested, habited, dighted, barbed, barded, clad, costume, shod, chausse, en grande tenue, sartorial, the soul of this man is his clothes.

N  woman, she, her, female, petticoat, feminality, muliebrity, womanhood, womankind, the sex, the fair, fair sex, softer sex, weaker vessel, dame, madam, madame, mistress, Mrs, lady, donna belle, matron, dowager, goody, gammer, Frau, frow, Vrouw, rani, good woman, good wife, squaw, wife, matronage, matronhood, bachelor girl, new woman, feminist, suffragette, suffragist, nymph, wench, grisette, girl, sissy, betty, cot betty, cotquean, henhussy, mollycoddle, muff, old woman, hen, bitch, sow, doe, roe, mare, she goat, Nanny goat, tabita, ewe, cow, lioness, tigress, vixen, gynecaeum, estrogen, oestrogen, consanguinity &c, paternity, lesbian, dyke, female, she-, feminine, womanly, ladylike, matronly, maidenly, wifely, womanish, effeminate, unmanly, gynecic, gynaecic, Pron, she, her, hers, ', a perfect woman nobly planned, a lovely lady garmented in white, das Ewig-Weibliche zieht uns hinan, earth's noblest thing, a woman perfected, es de vidrio la mujer, she moves a goddess and she looks a queen, the beauty of a lovely woman is like music, varium et mutabile semper femina, woman is the lesser man.