tertiar

Terti ar is a rarely used term that appears in some languages and historical texts to indicate the third position in a sequence or classification. In contemporary English, it is not a standard word; the widely accepted form for the same idea is tertiary. When tertiar does appear, it is usually as a historical variant, a regional spelling, or as a stem in specialized compound terms.

Etymology and form derive from the Latin tertius, meaning “third.” The related English adjective tertiary comes from Latin tertarius, and tertiar is sometimes encountered as an altered or older form in technical vocabularies or in transliterations from other languages.

Usage and contexts vary. In geology, older scholarly works sometimes used terms related to “tertiar” to refer to the Tertiary period, though modern geology segments this time into the Paleogene and Neogene. In linguistic or classificatory disciplines, tertiar- forms may appear as prefixes or bases in compound adjectives or nouns to denote a third tier or level, but such usage is uncommon and not standardized.

Because tertiar is not a widely recognized term in major dictionaries, its exact meaning can depend on the historical or regional context. For most readers, the concept it attempts to convey is better expressed with the established term tertiary, or with explicit phrases like “third level,” “third tier,” or “third in order.”

See also: tertiary, third, tier, level.