Mammoth Uncensored Word List:
60 words ending with an, 14 letters long

aeroelastician altitudinarian ambulancewoman antirepublican attitudinarian audiometrician brobdingnagian chondrichthyan circumforanean coastguardsman committeewoman contemporanean corpuscularian disciplinarian econometrician ephemeropteran ethnohistorian extrafallopian ferromagnesian footplatewoman frontierswoman handicraftsman heresthetician hypomixolydian ichthyosaurian infralapsarian intrafallopian latitudinarian microsporidian miscellanarian monoprionidian newspaperwoman nondinosaurian nonegalitarian nonlibertarian nonproletarian nonutilitarian opisthocoelian perfectibilian pharmacopoeian predestinarian premillenarian protohistorian pyrotechnician quadragenarian quodlibetarian sabermetrician sacramentarian sauropterygian septuagenarian sesquipedalian solitudinarian sportfisherman stegocephalian superterranean supralapsarian transcaucasian uniformitarian universitarian valetudinarian