What does indeclinable mean?
Indeclinable describes a word or grammatical form that does not change when its grammatical role changes. In particular, an indeclinable noun lacks case endings, so it has no separate forms for the nominative, accusative, or other cases required by an inflected language. The word is also used figuratively for something fixed, settled, or impossible to decline, as in “an indeclinable policy.” Its meaning should be distinguished from invariable, which can refer more generally to anything that remains unchanged, rather than specifically to a form lacking case endings. Indeclinable is especially useful when discussing grammatical systems and is more precise than saying that a word has “no plural” or “no different forms.” It also appears in both British and American English, although it is most common in formal linguistic and educational contexts.
Having no case endings and therefore remaining unchanged in form regardless of grammatical case.
"The noun was treated as indeclinable because it did not change when its case changed."
Most often used in grammatical description, especially of languages with extensive case systems.
A word or grammatical form that does not change for case, number, or gender.
"The appendix lists the indeclinables found in the text."
Usually used in grammatical or linguistic discussion; the plural is “indeclinables.”
The plural is used when referring to multiple indeclinable words or forms.
"The appendix identifies several indeclinables in the text."
Some words refuse to bend: an indeclinable keeps the same form whatever case the sentence demands.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does indeclinable come from?
The English word comes from Latin indeclinabilis, formed from the prefix in-, meaning “not,” and declinabilis, “capable of being declined.” The Latin root declinare means “to turn aside, lean, or decline.” English borrowed the term in the early 17th century for a word that cannot be declined, and it later developed the broader figurative sense of something unalterable or firmly fixed.
Related word forms
How indeclinable is actually used
This is primarily a grammatical term. It is more formal than general descriptions such as “does not change,” and it is often used in discussions of Latin, Greek, linguistics, or other inflected languages.
Easily confused with indeclinable
Both terms can describe a form that does not change, but in grammar an indeclinable specifically lacks case inflection, whereas invariable may mean unchanged in every respect.