Seeing as this question is posted in the Scrabble category, I've added some shorter words found in the Scrabble Tournament Words List, 2006 edition:

zax, zaxes, oxazine, oxazines, oxidize, oxidizes, oxidizer

(Zex and zexes also appear in other dictionaries, but not the Scrabble dictionary)

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anaxagorize, antibenzaldoxime, antioxidizer, antioxidizing, autoxidizability, autoxidizable, autoxidize, autoxidizer, axiomatization, axiomatizations, axiomatize, axiomatized, axiomatizes, axiomatizing, azodicarboxylic, azox, azoxazole, azoxime, azoxine, azoxonium, azoxy, azoxyanisole, azoxybenzene, azoxybenzoic, azoxynaphthalene, azoxyphenetole, azoxytoluidine,

benzaldoxime, benzantialdoxime, benzdioxazine, benzdioxdiazine, benzdioxtriazine, benzhydroxamic, benzofuroquinoxaline, benzoglyoxaline, benzoperoxide, benzophenoxazine, benzoquinoxaline, benzoxate, benzoxy, benzoxyacetic, benzoxycamphor, benzoxyphenanthrene, benztrioxazine,

chlordiazepoxide, chlordiazepoxides, contextualization, contextualizations, contextualize, contextualized, contextualizes, contextualizing,

decarboxylization, decarboxylize, deflexionize, deoxidization, deoxidizations, deoxidize, deoxidized, deoxidizer, deoxidizers, deoxidizes, deoxidizing, deoxygenization, deoxygenize, deoxygenized, deoxygenizes, deoxygenizing, desoxybenzoin, dextrinize, dextrosazone, diazeuxes, diazeuxis, diazohydroxide, dooxidize, doxologize, doxologized, doxologizing, dysoxidizable, dysoxidize,

epizeuxes, epizeuxis, epizeuxises, epoxidize, epoxidized, epoxidizes, epoxidizing, exauthorize, exauthorizeexc, excrementize, excursionize, excursionized, excursionizes, excursionizing, exhibitionize, existentialize, exoenzyme, exoenzymes, exoenzymic, exorcization, exorcize, exorcized, exorcizement, exorcizer, exorcizers, exorcizes, exorcizing, exordize, exostracize, experimentalize, experimentalized, experimentalizes, experimentalizing, experimentize, expermentized, expertize, expertized, expertizes, expertizing, extemporization, extemporizations, extemporize, extemporized, extemporizer, extemporizers, extemporizes, extemporizing, extensivization, extensivizations, exteriorization, exteriorizations, exteriorize, exteriorized, exteriorizes, exteriorizing, externalization, externalizations, externalize, externalized, externalizes, externalizing, externization, externize, exterritorialize, extrahazardous, extraquiz, extravaganza, extravaganzas, extrazodiacal, exzodiacal,

fuzzbox, fuzzboxes,

hexahydrobenzene, hexametrize, hexametrized, hexametrizes, hexametrizing, hydroxyazobenzene, hydroxybenzene, hydroxylization, hydroxylize, hydroxyzine, hydroxyzines, hyperdiazeuxis, hyperoxygenize, hyperoxygenized, hyperoxygenizing, hypodiazeuxis, hypozeuxis,

inoxidizable, inoxidize, inoxidized, inoxidizing, iodoxybenzene, isazoxy, isoalloxazine, isoalloxazines, isocarboxazid, isocarboxazids, isoxazine, isoxazole,

lexicalization, lexicalizations, lexicalize, lexicalized, lexicalizes, lexicalizing, lexiconize,

maxillozygomatic, maximization, maximizations, maximize, maximized, maximizer, maximizers, maximizes, maximizing, mazopexy, methoxybenzene, metoxazine,

nonexternalized, nonoxidizable, nonoxidization, nonoxidizing,

orthoxazin, orthoxazine, overoxidization, overoxidize, overoxidized, overoxidizing, oxadiazole, oxazepam, oxazepams, oxazin, oxazine, oxazines, oxazole, oxdiazole, oxidizability, oxidizable, oxidization, oxidizations, oxidize, oxidized, oxidizement, oxidizer, oxidizers, oxidizes, oxidizing, oxozone, oxozonide, oxozonides, oxyazo, oxybenzaldehyde, oxybenzene, oxybenzoic, oxybenzyl, oxygenizable, oxygenization, oxygenize, oxygenized, oxygenizement, oxygenizer, oxygenizes, oxygenizing, oxymetazoline, oxymetazolines, oxyphenbutazone, oxyphenbutazones, oxytonize,

paroxazine, paroxytonize, peroxidize, peroxidized, peroxidizement, peroxidizes, peroxidizing, phenoxazine, phenoxybenzamine, photooxidize, photooxidized, photooxidizes, photooxidizing, protoxidize, protoxidized,

quixotize,

recontextualize, recontextualized, recontextualizes, recontextualizing, reoxidize, reoxidized, reoxidizes, reoxidizing, reoxygenize, rhizotaxis, rhizotaxy,

schizaxon, semiexternalized, semioxidized, semioxygenized, skeezix, squeezebox, squeezeboxes, sulfamethoxazole, sulfamethoxazoles, sulfisoxazole, sulphamethoxazole, sulphamethoxazoles, sulphisoxazole,

taxidermize, taxidermized, taxidermizes, taxidermizing, texturize, texturized, texturizer, texturizers, texturizes, texturizing, toxosozin, trioxazine,

underoxidize, underoxidized, underoxidizing, unoxidizable, unoxidized, unoxygenized,

zanthoxyl, zanthoxyls, zanthoxylum, zax, zaxes, zeaxanthin, zelatrix, zelatrixes, zeroaxial, zeuxite, zeuxites, zex, zexes, zoopraxiscope, zootaxies, zootaxonomist, zootaxy, zootoxic, zootoxin, zootoxins, zooxanthella, zooxanthellae, zooxanthin, zygomaticomaxillary, zygomaxillare, zygomaxillary, zygotaxis, zymotoxic