The List
There are 717 5 letter words with A as the first letter. The highest scoring is ABUZZ at 25 points in Scrabble. 281 carry three or more vowels, which makes them useful for dumping a vowel-clogged rack.
AAHEDAALIIAARGHAARTIABACAABACIABACKABACSABAFTABAKAABAMPABANDABASEABASHABASKABATEABAYAABBASABBEDABBESABBEYABBOTABCEEABEAMABEARABELEABETSABHORABIDEABIESABLEDABLERABLESABLETABLOWABMHOABODEABOHMABOILABOMAABOONABORDABOREABORTABOUTABOVEABRAMABRAYABRIMABRINABRISABSEYABSITABUNAABUNEABUSEABUTSABUZZABYESABYSMABYSSACAISACARIACCASACCOYACERBACERSACETAACHARACHEDACHESACHOOACIDSACIDYACINGACINIACKEEACKERACMESACMICACNEDACNESACOCKACOLDACORNACREDACRESACRIDACTEDACTINACTONACTORACUTEACYLSADAGEADAPTADAWSADAYSADDAXADDEDADDERADDIOADDLEADEEMADEPTADHANADIEUADIOSADITSADMANADMENADMINADMITADMIXADOBEADOBOADOPTADOREADORNADOWNADOZEADRADADREDADSUMADUKIADULTADUNCADUSTADVEWADYTAADZEDADZESAECIAAEDESAEGISAEONSAERIEAEROSAESIRAFALDAFARAAFARSAFEARAFFIXAFIREAFLAJAFOOTAFOREAFOULAFRITAFROSAFTERAGAINAGAMAAGAMIAGAPEAGARSAGASTAGATEAGAVEAGAZEAGENEAGENTAGERSAGGERAGGIEAGGRIAGGROAGGRYAGHASAGILAAGILEAGINGAGIOSAGISMAGISTAGITAAGLEEAGLETAGLEYAGLOOAGLOWAGLUSAGMASAGOGEAGONEAGONSAGONYAGOODAGORAAGREEAGRIAAGRINAGUEDAGUESAGUNAAGUTIAHEADAHEAPAHENTAHIGHAHINDAHINGAHINTAHOLDAHULLAHURUAIDASAIDEDAIDERAIDESAIDOIAIDOSAIERYAIGASAIGHTAILEDAIMEDAIMERAINEEAINGAAIOLIAIREDAIRERAIRNSAIRTHAIRTSAISLEAITCHAITUSAIVERAIZLEAJIVAAJUGAAJWANAKEESAKELAAKENEAKINGAKITAAKKASALAAPALACKALAMOALANDALANEALANGALANSALANTALAPAALAPSALARMALARYALATEALAYSALBASALBEEALBUMALCIDALCOSALDEAALDERALDOLALECKALECSALEFSALEFTALEPHALERTALEWSALEYEALFASALGAEALGALALGASALGIDALGINALGORALGUMALIASALIBIALIENALIFSALIGNALIKEALINEALISTALIVEALIYAALKIEALKOSALKYDALKYLALLAYALLEEALLELALLEYALLISALLODALLOTALLOWALLOYALLYLALMAHALMASALMEHALMESALMUDALMUGALODSALOEDALOESALOFTALOHAALOINALONEALONGALOOFALOOSALOUDALOWEALPHAALTARALTERALTHOALTOSALULAALUMSALUREALWAYAMAHSAMAINAMASSAMATEAMAUTAMAZEAMBANAMBERAMBITAMBLEAMBOSAMBRYAMEBAAMEERAMENDAMENEAMENSAMENTAMIASAMICEAMICIAMIDEAMIDOAMIDSAMIESAMIGAAMIGOAMINEAMINOAMINSAMIRSAMISSAMITYAMLASAMMANAMMONAMMOSAMNIAAMNICAMNIOAMOKSAMOLEAMONGAMORTAMOURAMOVEAMOWTAMPEDAMPLEAMPLYAMPULAMRITAMUCKAMUSEAMYLSANANAANATAANCHOANCLEANCONANDROANEARANELEANENTANGASANGELANGERANGLEANGLOANGRYANGSTANIGHANILEANILSANIMAANIMEANIMIANIONANISEANKERANKHSANKLEANKUSANLASANNALANNASANNATANNEXANNOYANNULANOASANODEANOLEANOMYANSAEANTAEANTARANTASANTEDANTESANTICANTISANTRAANTREANTSYANVILANYONAORTAAPACEAPAGEAPAIDAPARTAPAYDAPAYSAPEAKAPEEKAPERSAPERTAPERYAPGARAPHIDAPHISAPIANAPINGAPIOLAPISHAPISMAPNEAAPODEAPODSAPOOPAPORTAPPALAPPAYAPPELAPPLEAPPLYAPPROAPPUIAPPUYAPRESAPRONAPSESAPSISAPSOSAPTEDAPTERAPTLYAQUAEAQUASARABAARAKSARAMEARARSARBASARBORARCEDARCOSARCUSARDEBARDORARDRIAREADAREAEAREALAREARAREASARECAAREDDAREDEAREFYAREICARENAARENEAREPAAREREARETEARETSARETTARGALARGANARGILARGLEARGOLARGONARGOTARGUEARGUSARHATARIASARIELARIKIARILSARIOTARISEARISHARKEDARLEDARLESARMEDARMERARMETARMILARMORARNASARNUTAROBAAROHAAROIDAROMAAROSEARPASARPENARRAHARRASARRAYARRETARRISARROWARSISARSONARTALARTELARTICARTISARTSYARUHEARUMSARVALARVOSARYLSASANAASCOTASCUSASDICASHEDASHENASHESASHETASIDEASKEDASKERASKEWASKOIASKOSASPENASPERASPICASPISASPROASSAIASSAMASSAYASSETASSEZASSOTASTERASTIRASTUNASWAYASWIMASYLAATAPSATAXYATIGIATILTATIMYATLASATMANATMASATOCSATOKEATOKSATOLLATOMSATOMYATONEATONYATOPYATRIAATRIPATTAPATTARATTICATUASAUDADAUDIOAUDITAUGERAUGHTAUGURAULASAULICAULOIAULOSAUMILAUNESAUNTSAUNTYAURAEAURALAURARAURASAUREIAURESAURICAURISAURUMAUTOSAUXINAVAILAVALEAVANTAVASTAVELSAVENSAVERSAVERTAVGASAVIANAVINEAVIONAVISEAVISOAVIZEAVOIDAVOWSAVYZEAWAITAWAKEAWARDAWAREAWARNAWASHAWATOAWAVEAWAYSAWDLSAWEELAWETOAWFULAWINGAWMRYAWNEDAWNERAWOKEAWOLSAWORKAXELSAXIALAXILEAXILSAXINGAXIOMAXIONAXITEAXLEDAXLESAXMANAXMENAXOIDAXONEAXONSAYAHSAYELPAYGREAYINSAYONTAYRESAYRIEAZANSAZIDEAZIDOAZINEAZLONAZOICAZOLEAZONSAZOTEAZOTHAZUKIAZUREAZURNAZURYAZYGYAZYMEAZYMS