idioticon UK /ˌɪdɪˈəʊtɪk(ə)n/US /ˌɪdiˈoʊtək(ə)n/ noun1 •A dictionary of a specific dialect, or of the words and phrases peculiar to one part of a country.IDIO′TICON. (Gr[eek]) A word of frequent use in Germany, signifying a dictionary confined to a particular dialect, or containing words and phrases peculiar to one part of a country. — 1842 formsidiotica · idioticons