sui generis

adjective

sui ge·​ner·​is ˌsü-ˌī-ˈje-nə-rəs  ˌsü-ē-ˈje- 

-ˈge-

: constituting a class alone : unique, peculiar

Did you know?

English contains many terms that ultimately trace back to the Latin forms gener- or "genus" (which are variously translated as "birth," "race," "kind," and "class"). Offspring of those roots include "general," "generate," "generous," "generic," "degenerate," and "gender." But "sui generis" is truly a one-of-a-kind "gener-" descendant that English speakers have used for singular things since the late 1600s. Its earliest uses were in scientific contexts, where it identified substances, principles, diseases, and even rocks that were unique or that seemed to be the only representative of their class or group. By the early 1900s, however, "sui generis" had expanded beyond solely scientific contexts, and it is now used more generally for anything that stands alone.

Synonyms

• only
• one
• lone
• special
• unique

Examples of sui generis in a Sentence

among history's greats Leonardo da Vinci is often considered sui generis—a man of such stupendous genius that the world may never see his like again

Recent Examples on the Web

Almost all of Weill’s projects were sui generis, rejecting routine and experimenting anew. —Alex Ross, New Yorker, 14 Apr. 2025

But the widespread panic and concerted opposition within Jordan suggest that the looming crisis is sui generis in its severity. —Curtis R. Ryan, Foreign Affairs, 25 Mar. 2025

Dylan, of course, is sui generis, the kind of transcendent cultural avatar who comes along once in a century. —Thomas Doherty, The Hollywood Reporter, 19 Feb. 2025

That decades-old advertising slogan succinctly captures the brand promise of the sui generis American business that marks its 80th anniversary this year. —Cynthia Littleton, Variety, 6 Mar. 2025

Word History

Etymology

Latin, of its own kind

First Known Use

1615, in the meaning defined above

Rhymes for sui generis

• ungenerous
• generous

Legal Definition

sui generis

adjective

sui ge·​ner·​is ˈsü-ˌī-ˈje-nə-rəs, ˈsü-ē- 

: constituting a class alone : unique or particular to itself

the lawyer's…ad that makes no distinction among various legal and factual nuances in each sui generis case has the potential to mislead

—National Law Journal

Etymology

Latin, of its own kind