ential

Ential is a productive suffix in English, not a standalone word. It is used to form adjectives (and occasionally nouns) that describe a relation to or a characteristic of a root concept. Words ending in -ential include essential, incidental, influential, existential, potential, credential, and confidential.

Etymology and formation: The suffix comes from Latin -ent-ial, and reached English via Old French or directly from Latin. It combines with a range of stems, and the consonant before -ential may vary, sometimes producing forms such as dential (as in incidental, confidential) or ential as in essential, existential, potential.

Usage and meaning: Although many -ential words share the sense of relation to the root, their particular meanings differ. Essential means necessary, incidental means secondary by accident, influential denotes having influence, existential relates to existence, potential indicates possibility, credential refers to a document or qualification, and confidential describes information intended to be kept private. The precise sense is determined by the root word and the historical development of the term.

Note: The suffix is more about derivational morphology than a fixed semantic field, and not all -ential words derive from the same Latin root. In modern English, -ential words appear across science, philosophy, law, and everyday vocabulary.