tungumálum
Tungumálum is the dative plural form of the Icelandic noun tungumál, which means “language” or “tongue” in English. In Icelandic grammar, tungumál refers to a language, and tungumálum is the form used when the dative case is required for multiple languages. This form appears in sentences where the dative case governs the noun, such as after certain prepositions or verbs that take the dative.
As a grammatical form, tungumálum is not a separate concept from tungumál; it is a case-based inflection
Etymology-wise, tungumál is a compound of Old Norse elements meaning “tongue” (tunga) and “speech” or “language”
See also: tungumál, Icelandic noun inflection, Icelandic grammar, Old Norse etymology.