The List
There are 654 7 letter words with I as the first letter. The highest scoring is IZZARDS at 26 points in Scrabble. 509 carry three or more vowels, which makes them useful for dumping a vowel-clogged rack.
IAMBICSIAMBISTICEBALLICEBERGICEBOATICECAPSICEFALLICELESSICELIKEICEPACKICEWINEICHABODICHNITEICHTHICICHTHYSICICLEDICICLESICINESSICKIESTICKLESTICONIFYICONISEICONIZEICTERICICTERIDICTERUSICTUSESIDEALLYIDEATEDIDEATESIDEATUMIDENTICIDIOTCYIDIOTICIDLESSEIDOLISEIDOLISMIDOLISTIDOLIZEIDYLISTIDYLLICIFFIESTIGARAPEIGNAROSIGNATIAIGNEOUSIGNITEDIGNITERIGNITESIGNITORIGNOBLEIGNOBLYIGNOREDIGNORERIGNORESIGUANASIGUANIDIJTIHADIKEBANAILEITISILEUSESILIACUSILKADAYILLAPSEILLEGALILLIADSILLICITILLIPESILLITESILLITICILLNESSILLOGICILLUDEDILLUDESILLUMEDILLUMESILLUPISILLUVIAIMAGERSIMAGERYIMAGINEIMAGINGIMAGISMIMAGISTIMAGOESIMAMATEIMARETSIMBALMSIMBARKSIMBASEDIMBASESIMBATHEIMBIBEDIMBIBERIMBIBESIMBIZOSIMBLAZEIMBOSKSIMBOSOMIMBOWERIMBRASTIMBROWNIMBRUEDIMBRUESIMBRUTEIMBUINGIMBURSEIMITANTIMITATEIMMASKSIMMENSEIMMERGEIMMERSEIMMEWEDIMMIXEDIMMIXESIMMORALIMMUNESIMMUREDIMMURESIMPACTSIMPAINTIMPAIRSIMPALASIMPALEDIMPALERIMPALESIMPANELIMPARKSIMPARLSIMPARTSIMPASSEIMPASTEIMPASTOIMPAVEDIMPAVESIMPAVIDIMPAWNSIMPEACHIMPEARLIMPEDEDIMPEDERIMPEDESIMPEDORIMPENDSIMPERIAIMPERILIMPETUSIMPHEESIMPIETYIMPINGEIMPINGSIMPIOUSIMPLANTIMPLATEIMPLEADIMPLETEIMPLIEDIMPLIESIMPLODEIMPLOREIMPONEDIMPONESIMPORTSIMPOSEDIMPOSERIMPOSESIMPOSEXIMPOSTSIMPOUNDIMPOWERIMPREGNIMPRESAIMPRESEIMPRESSIMPRESTIMPRINTIMPROVEIMPROVSIMPUGNSIMPULSEIMPURERIMPUTEDIMPUTERIMPUTESINANELYINANESTINANGASINANITYINAPTLYINARMEDINBEINGINBOARDINBOUNDINBOXESINBREAKINBREDSINBREEDINBRINGINBUILTINBURSTINCAGEDINCAGESINCANTSINCASEDINCASESINCAVEDINCAVESINCEDEDINCEDESINCENSEINCENTSINCEPTSINCHASEINCHERSINCHINGINCHPININCIPITINCISALINCISEDINCISESINCISORINCITEDINCITERINCITESINCIVILINCLASPINCLINEINCLIPSINCLOSEINCLUDEINCOMERINCOMESINCONIEINCONNUINCROSSINCRUSTINCUBUSINCUDALINCUDESINCURVEINCUSEDINCUSESINDABASINDAMININDARTSINDENESINDENTSINDEWEDINDEXALINDEXEDINDEXERINDEXESINDICANINDICESINDICIAINDICTSINDIGENINDIGOSINDITEDINDITERINDITESINDIUMSINDOLESINDOORSINDORSEINDOWEDINDOXYLINDRAFTINDRAWNINDUCEDINDUCERINDUCESINDUCTSINDUINGINDULGEINDULININDULTSINDUNASINDUSIAINDWELLINDWELTINEARTHINEDITAINEPTERINEPTLYINERTERINERTIAINERTLYINEXACTINFALLSINFAMEDINFAMESINFANCYINFANTAINFANTEINFANTSINFARCTINFARESINFAUNAINFAUSTINFECTSINFEFTSINFEOFFINFERNOINFESTSINFIDELINFIELDINFIGHTINFILLSINFIMUMINFIRMSINFIXEDINFIXESINFLAMEINFLATEINFLECTINFLICTINFLOWSINFOLDSINFORCEINFORMSINFRACTINFULAEINFUSEDINFUSERINFUSESINGATESINGENERINGENUEINGENUSINGESTAINGESTSINGINESINGLOBEINGOINGINGOTEDINGRAFTINGRAININGRATEINGRESSINGROSSINGROUPINGROWNINGULFSINGULPHINHABITINHALEDINHALERINHALESINHAULSINHAUSTINHERCEINHEREDINHERESINHERITINHIBININHIBITINHOOPSINHUMANINHUMEDINHUMERINHUMESINISLEDINISLESINITIALINJECTSINJELLYINJERASINJOINTINJUNCTINJUREDINJURERINJURESINKBLOTINKHORNINKHOSIINKIESTINKLESSINKLIKEINKLINGINKOSISINKPADSINKPOTSINKSPOTINKWELLINKWOODINLACEDINLACESINLANDSINLAYERINLIERSINLOCKSINLYINGINMATESINNAGESINNARDSINNERLYINNERVEINNINGSINNLESSINNYARDINOCULAINORBEDINOSINEINOSITEINPHASEINPOURSINQILABINQUEREINQUESTINQUIETINQUIREINQUIRYINROADSINSANERINSANIEINSCAPEINSCULPINSEAMSINSECTSINSEEMSINSERTSINSHELLINSHIPSINSHOREINSIDERINSIDESINSIGHTINSIGNEINSINEWINSIPIDINSISTSINSNAREINSOFARINSOLESINSOOTHINSOULSINSPANSINSPECTINSPIREINSTALLINSTALSINSTANTINSTARSINSTATEINSTEADINSTEPSINSTILLINSTILSINSULAEINSULARINSULININSULSEINSULTSINSUREDINSURERINSURESINSWEPTINSWINGINTAGLIINTAKESINTEGERINTENDSINTENSEINTENTSINTERIMINTERNEINTERNSINTHRALINTIMAEINTIMALINTIMASINTINESINTITLEINTOMBSINTONEDINTONERINTONESINTORTSINTRADAINTRANTINTREATINTROFYINTROITINTROLDINTRONSINTRUDEINTRUSTINTUITSINTURNSINTUSESINTWINEINTWISTINULASEINULINSINURINGINURNEDINUTILEINVADEDINVADERINVADESINVALIDINVEIGHINVENITINVENTSINVERSEINVERTSINVESTSINVEXEDINVIOUSINVITALINVITEDINVITEEINVITERINVITESINVOICEINVOKEDINVOKERINVOKESINVOLVEINWALLSINWARDSINWEAVEINWICKSINWINDSINWORKSINWOUNDINWOVENINWRAPSINYALASIODATEDIODATESIODIDESIODINESIODISEDIODISERIODISESIODISMSIODIZEDIODIZERIODIZESIODURETIOLITESIONISEDIONISERIONISESIONIUMSIONIZEDIONIZERIONIZESIONOGENIONOMERIONONESIPECACSIPOMOEAIRACUNDIRATELYIRATESTIRELESSIRENICSIRIDEALIRIDIALIRIDIANIRIDISEIRIDIUMIRIDIZEIRISATEIRISINGIRKSOMEIRONERSIRONIERIRONIESIRONINGIRONISEIRONISTIRONIZEIRONMANIRONMENIRRUPTSISABELSISAGOGEISATINEISATINSISCHIALISCHIUMISLANDSISLEMANISLEMENISLETEDISMATICISOAMYLISOBAREISOBARSISOBASEISOBATHISOCHORISODICAISODOMAISODONTISODOSEISOETESISOFORMISOGAMYISOGENYISOGONEISOGONSISOGONYISOGRAMISOGRIVISOHELSISOHYETISOKONTISOLATEISOLEADISOLINEISOLOGSISOMEREISOMERSISONOMEISONOMYISOPACHISOPODSISOSPINISOTACHISOTONEISOTOPEISOTOPYISOTRONISOTYPEISOZYMEISSUANTISSUERSISSUINGISTANASISTHMICISTHMUSITACISMITALICSITCHIERITCHILYITCHINGITEMINGITEMISEITEMIZEITERANTITERATEIVORIEDIVORIESIVORISTIVRESSEIVYLIKEIXODIDSIZZARDS