A fifteen letter word that contains the letters atragiclostnoun is congratulations!!!
There are 5757 fifteen-letter words in English. Click here for the full list. Here are a few words:BIOGENETICALLYABORIGINALITIESABSORBABILITIESABSORBEFACIENTSABSORPTIOMETERSABSTRACTIONISMSABSTRACTIONISTSACANTHOCEPHALANACCEPTABILITIESACCEPTINGNESSESACCESSARINESSESACCESSIBILITIESACCESSORINESSESACCIDENTALITIESACCIDENTOLOGIESACCLIMATISATIONACCLIMATIZATIONACCOMMODATINGLYACCOMMODATIONALACCOMPLISHMENTSACCOUNTABLENESSACCOUNTANTSHIPSACCULTURATIONALACETOPHENETIDINACETYLSALICYLICACHONDROPLASIASACHONDROPLASTICACHROMATICITIESACHROMATISATIONACHROMATIZATIONACIDIMETRICALLYACKNOWLEDGEABLEACKNOWLEDGEABLYACKNOWLEDGEMENTACKNOWLEDGMENTSACQUIRABILITIESACQUISITIVENESSACRIMONIOUSNESSACROPARESTHESIAACTINOBIOLOGIES
Leather
feedback
Cheetah
Copters
Rotate
Traditions, iterations
seduces
babes
The word is fetid.
Euphemism.
The letters spell Stockholm. The city is the capital city of Sweden.