Mammoth Uncensored Word List:
19 words that are 14 letters long beginning with j in the mammoth uncensored word list.

jargonisations jargonizations jellifications jerrymandering jingoistically johnsongrasses jollifications journalisation journalization jurisdictional jurisprudences justiciability justiciarships justifiability justifications juvenilenesses juxtaarticular juxtapositions juxtavesicular