There are 441 fifteen-letter words containing A, C, H, I and S, https://www.bestwordlist.com/c/a/5/15letterwordswithachis.htm
ACCOMPLISHMENTS ACCOUNTANTSHIPS ACHONDROPLASIAS ACHONDROPLASTIC
ACHROMATICITIES ACHROMATISATION ACROPARESTHESIA ACTINOCHEMISTRY
ACTINOTHERAPIES ADIATHERMANCIES AFFRANCHISEMENT ALCOHOLISATIONS
ALCOHOLIZATIONS ALCOHOLOMETRIES ANAESTHETICALLY ANARCHISTICALLY
ANTAPHRODISIACS ANTHROPOPHOBICS ANTHROPOPSYCHIC ANTIALCOHOLISMS
ANTIAPHRODISIAC ANTIARRHYTHMICS ANTICHOLESTEROL ANTICHRISTIANLY
ANTIHELMINTHICS ANTIHISTAMINICS ANTIMONARCHISTS ANTIPHLOGISTICS
ANTISYPHILITICS ANTITHROMBOTICS APPRENTICEHOODS APPRENTICESHIPS
ARACHNOIDITISES ARCHAEOBOTANIES ARCHAEOBOTANIST ARCHAEOMETRISTS
ARCHAEZOOLOGIES ARCHEOBOTANISTS ARCHEOMAGNETISM ARCHEOZOOLOGIES
ARCHEOZOOLOGIST ARCHGENETHLIACS ARCHIDIACONATES ARCHIEPISCOPACY
ARCHIEPISCOPATE ARCHPRIESTHOODS ARCHPRIESTSHIPS ASTROPHYSICALLY
ASTROPHYSICISTS ATHEROSCLEROSIS ATHEROSCLEROTIC ATMOSPHERICALLY
AUTHENTICATIONS AUTOSCHEDIASTIC AUTOSCHEDIAZING BACCHANALIANISM
BACKSCRATCHINGS BACTERIOPHAGIES BACTERIOPHAGOUS BATRACHOPHOBIAS
BIBLIOTHECARIES BIOGEOCHEMICALS BRACHIOSAURUSES BRACHISTOCHRONE
BRACHYCEPHALICS BRACHYCEPHALIES BRACHYCEPHALISM BRACHYDACTYLIES
BRACHYDACTYLISM BRACHYDIAGONALS BRACHYPINAKOIDS BRACHYTHERAPIES
BRAUNSCHWEIGERS BRONCHODILATORS BRONCHOGRAPHIES BRONCHOSCOPICAL
CANTHAXANTHINES CATECHISTICALLY CATECHUMENSHIPS CATHETERISATION
CATHODOGRAPHIES CATHOLICISATION CERVICOGRAPHIES CHALCOGRAPHISTS
CHAMBERLAINSHIP CHANCELLORSHIPS CHANGEABILITIES CHANNELISATIONS
CHANNELIZATIONS CHANNELOPATHIES CHAPTALISATIONS CHAPTALIZATIONS
CHARACTERISABLE CHARACTERISTICS CHARGEABILITIES CHEMICOPHYSICAL
CHEMOPSYCHIATRY CHEMOTAXONOMIES CHEMOTAXONOMIST CHEMOTHERAPISTS
CHENOPODIACEOUS CHLORITISATIONS CHLORITIZATIONS CHLOROTHIAZIDES
CHLORPROMAZINES CHLORPROPAMIDES CHLORTHALIDONES CHOLESTEROLEMIA
CHOLESTYRAMINES CHOLINESTERASES CHONDRICHTHYANS CHONDROCRANIUMS
CHORIOALLANTOIS CHRESTOMATHICAL CHROMATICNESSES CHROMATOLOGISTS
CHROMOTHERAPIES CHRONOTHERAPIES CINCHONISATIONS CINCHONIZATIONS
CLAUSTROPHILIAS CLAUSTROPHOBIAS CLIMATOGRAPHIES COCHAIRMANSHIPS
COMMANDANTSHIPS COMMISSARYSHIPS COMPOTATIONSHIP COMPUTERPHOBIAS
CONSERVATORSHIP CONSULTANTSHIPS CORINTHIANISING COUNTERSHADINGS
CRASHWORTHINESS CRYPTAESTHESIAS CRYPTOGRAPHISTS CYBERCHONDRIACS
CYPROHEPTADINES CYTOPATHOLOGIES CYTOPATHOLOGIST DACTYLOGRAPHIES
DECHLORINATIONS DECHRISTIANISED DECHRISTIANISES DECHRISTIANIZED
DECHRISTIANIZES DEPHLOGISTICATE DERMATOGLYPHICS DETACHABILITIES
DIASTROPHICALLY DICHLOROETHANES DICHOTOMISATION DICHROMATICISMS
DISACCHARIDASES DISENCHANTINGLY DISENCHANTMENTS DISENFRANCHISED
DISENFRANCHISES DISINHERITANCES DOLICHOSAURUSES DORSIBRANCHIATE
ECHINODERMATOUS ECHOCARDIOGRAMS ECTOMYCORRHIZAS ELECTROGRAPHIES
ENCEPHALITOGENS ENCEPHALOTOMIES ENFRANCHISEMENT ESOPHAGOSCOPIES
ETHERIFICATIONS ETHNOHISTORICAL EUPHEMISTICALLY EUTROPHICATIONS
FEATHERSTITCHED FEATHERSTITCHES FETISHISTICALLY GEODEMOGRAPHICS
GEOSTROPHICALLY GLOSSOGRAPHICAL GRAPHICALNESSES HALLUCINOGENICS
HAMAMELIDACEOUS HARMONISTICALLY HARPSICHORDISTS HEARTSICKNESSES
HEMICRYSTALLINE HEMOCHROMATOSIS HENDECASYLLABIC HEPATICOLOGISTS
HERESTHETICIANS HETEROSCEDASTIC HETEROSOCIALITY HIBERNICISATION
HIERACOSPHINGES HIERACOSPHINXES HISTOCHEMICALLY HISTOCOMPATIBLE
HISTOPATHOLOGIC HISTORIOGRAPHIC HOLOBLASTICALLY HOLOCRYSTALLINE
HOMOCHROMATISMS HOMOPLASTICALLY HOMOSOCIALITIES HUMIDIFICATIONS
HYDROCORALLINES HYDRODYNAMICIST HYDROSTATICALLY HYGROSCOPICALLY
HYLOZOISTICALLY HYPERACTIVITIES HYPERCALCAEMIAS HYPERCATABOLISM
HYPERGLYCAEMIAS HYPERPHYSICALLY HYPERURICAEMIAS HYPERVIGILANCES
HYPOCHONDRIASES HYPOCHONDRIASIS HYPOCHONDRIASMS HYPOCHONDRIASTS
HYPOCRYSTALLINE HYPSOMETRICALLY ICHTHYOPHAGISTS ICHTHYOSAURIANS
ICHTHYOSAURUSES ICOSITETRAHEDRA INHARMONICITIES INTERSCHOLASTIC
IONOSPHERICALLY ISOTHIOCYANATES KINESTHETICALLY LEUCOCYTHAEMIAS
LEXICOGRAPHISTS LICENTIATESHIPS LISSENCEPHALIES LISSENCEPHALOUS
LITHOCHROMATICS MACHINABILITIES MACRENCEPHALIAS MACRENCEPHALIES
MASOCHISTICALLY MATHEMATICISING MATRIARCHALISMS MECHANISTICALLY
MECHANOMORPHISM MEGALOCEPHALIES MESATICEPHALIES MESATICEPHALOUS
METACHROMATISMS METAMATHEMATICS METAPHYSICISING METAPHYSICIZING
MICROAEROPHILES MICROBAROGRAPHS MICROPHYSICALLY MISCHARACTERISE
MISCHARACTERIZE MONOCHROMATISMS MONOSACCHARIDES MORPHINOMANIACS
MULTICHARACTERS MUSICOTHERAPIES MYOCARDIOGRAPHS NEUROPSYCHIATRY
NONACHIEVEMENTS NONCHARISMATICS NONHISTORICALLY NONHYSTERICALLY
NONPSYCHIATRIST NONPSYCHOACTIVE NONTHEISTICALLY NUDIBRANCHIATES
OLIGOCYTHAEMIAS OLIGOSACCHARIDE OPHTHALMOSCOPIC ORCHESOGRAPHIES
ORCHESTRATIONAL ORGANOCHLORINES ORTHOCHROMATISM ORTHOPSYCHIATRY
OSCILLOGRAPHIES OSTEOARTHRITICS OSTEOPATHICALLY PACHYMENINGITIS
PANTHEISTICALLY PARASYMPATHETIC PARTHENOCARPIES PATHOGENICITIES
PATRIARCHALISMS PHALLOCENTRISMS PHARISAICALNESS PHARMACEUTICALS
PHARMACOGNOSIES PHARMACOGNOSIST PHARMACOGNOSTIC PHARMACOLOGISTS
PHARMACOPOEIANS PHARMACOPOEISTS PHARMACOPOLISTS PHARYNGOSCOPIES
PHENAKISTOSCOPE PHENOMENALISTIC PHILOSOPHICALLY PHLOGISTICATING
PHONEMICISATION PHONETICISATION PHOSPHOCREATINE PHOSPHOCREATINS
PHOTODISSOCIATE PHOTODUPLICATES PHOTOELASTICITY PHTHALOCYANINES
PHYLLOSILICATES PHYSICOCHEMICAL PHYSIOGRAPHICAL PHYSIOLOGICALLY
PITHECANTHROPUS PLAGIOCEPHALIES PLAINCLOTHESMAN PLAINCLOTHESMEN
POLYCHROMATISMS POLYSACCHARIDES POLYSYNTHETICAL POSTHEMORRHAGIC
PREANAESTHETICS PREHISTORICALLY PROCURATORSHIPS PSEPHOLOGICALLY
PSEUDEPIGRAPHIC PSYCHEDELICALLY PSYCHIATRICALLY PSYCHOACOUSTICS
PSYCHOANALYSING PSYCHOANALYZING PSYCHOBIOGRAPHY PSYCHOCHEMICALS
PSYCHODELICALLY PSYCHOGENETICAL PSYCHOGENICALLY PSYCHOGERIATRIC
PSYCHOGRAPHICAL PSYCHOHISTORIAN PSYCHOLOGICALLY PSYCHOMETRICIAN
PSYCHOSEXUALITY PSYCHOTHERAPIES PSYCHOTHERAPIST PSYCHROMETRICAL
PYROTECHNICIANS RADICULOPATHIES REORCHESTRATING REORCHESTRATION
RHINENCEPHALONS RHINOSCLEROMATA SACCHARIMETRIES SACCHARISATIONS
SACCHARIZATIONS SACCHAROMETRIES SADOMASOCHISTIC SAPROPHYTICALLY
SCAPHOCEPHALICS SCAPHOCEPHALIES SCAPHOCEPHALISM SCEUOPHYLACIUMS
SCHEMATISATIONS SCHEMATIZATIONS SCHILLERISATION SCHILLERIZATION
SCHISTOSOMIASES SCHISTOSOMIASIS SCHIZOAFFECTIVE SCHOLARLINESSES
SCHOOLMASTERING SCHOOLMASTERISH SCHOOLTEACHINGS SCLEROTHERAPIES
SCRATCHBUILDERS SCRATCHBUILDING SCRIMSHANDERING SEARCHABILITIES
SEARCHINGNESSES SEISMOGRAPHICAL SELENOGRAPHICAL SEMILOGARITHMIC
SERVOMECHANICAL SERVOMECHANISMS SHOCKUMENTARIES SKETCHABILITIES
SOCIOHISTORICAL SOPHISTICATEDLY SOPHISTICATIONS SPECTROGRAPHIES
SPEECHIFICATION SPHERICALNESSES SPINTHARISCOPES SPIROCHAETAEMIA
SPLANCHNOLOGIES STAPHYLOPLASTIC STEEPLECHASINGS STEGOCEPHALIANS
STEREOGRAPHICAL STOECHIOLOGICAL STOICHIOLOGICAL STRAIGHTJACKETS
STRATIGRAPHICAL STRATOSPHERICAL SULPHACETAMIDES SUPERCARGOSHIPS
SYCOPHANTICALLY SYMPATHECTOMIES SYMPATHETICALLY SYMPATHOMIMETIC
SYNCHRONISATION SYNCHRONISTICAL SYNCHRONIZATION SYNECDOCHICALLY
TECHNICALNESSES THALASSOCRACIES THALASSOGRAPHIC THALATTOCRACIES
THEATRICALISING THEATRICALITIES THEOSOPHISTICAL THICKHEADEDNESS
THORACOCENTESIS THORACOPLASTIES TRANSHISTORICAL TRICHINISATIONS
TRICHINIZATIONS TRICHOMONACIDES TRISOCTAHEDRONS UNCHRISTIANISED
UNCHRISTIANISES UNCHRISTIANIZED UNCHRISTIANIZES UNCHRISTIANLIKE
UNPHILOSOPHICAL UNSOPHISTICATED WAPPENSCHAWINGS WHIMSICALNESSES
ZYGOBRANCHIATES