Definition of indeclinable in English:

indeclinable

adjective

Grammar
  • (of a noun, pronoun, or adjective in a highly inflected language) having no inflections.

    • ‘The Adverbial Compounds generally take the neuter gender and are indeclinable.’
    • ‘The verbal indeclinable participle may be formed from transitive and intransitive verbs.’
    • ‘In Latin, prepositions are indeclinable (they do not have endings); the object of a Latin preposition will be in either the ablative or the accusative case.’
    • ‘In the absence of a declension class (indeclinable nouns), neuter agreement is assigned.’
    • ‘However, another relatively modern dictionary states that nostras is an indeclinable Latin adjective used in medicine in reference to diseases with external clinical aspects analogous to those of exotic diseases, i.e. unusual, different or strange diseases.’

Origin

Late Middle English: via French from Latin indeclinabilis, from in- not + declinabilis able to be inflected (see decline).

Pronunciation:

indeclinable

/ˌɪndɪˈklʌɪnəb(ə)l/