EtymEx

cogent

/ˈkoʊdʒənt/adjective

Clear, logical, and persuasive

From Latin cō (Together) + Latin agō (Drive).

Lineage

cō

agō

LatinRomanceGermanicnot directly attestedSelect a stage for details, or drag it

The story

Picture a driver pushing a herd into a tight group: that physical image lies behind Latin cōgere, “to drive together,” formed from cō- (“together”) and agere (“to drive”). Its participle cōgēns described something compelling, and French passed the form along as cogent, meaning “necessary” or “urgent.” English adopted it in the 1650s, shifting the emphasis from force on bodies to force on belief: a cogent argument drives your thoughts toward agreement. The same Latin agere also gave English agent and agenda—one who acts, and the things to be done—so a cogent case is, in a sense, an argument that gets your mind moving in one direction.

Modern usage

Urban Dictionary entries use “Cogent” for a low-cost, low-quality internet bandwidth provider and, separately, as an obscure vulgar adjective.

Heard in
internet slang · obscure vulgar slang

Related words

Confused with
coherent, congenial

Words from the same roots

cō · Latin, ‘Together; a combining form of com-’

Derivedcooperate, cohesion, combine, converge

agō · Latin, ‘Drive, set in motion, or do’

Derivedagent, agenda, agile, act

Sources