cogently

The adverb 'cogently' is built upon its adjective form 'cogent', which originates from the Latin verb cogere, meaning 'to compel' or 'to drive together'. This verb itself is a compound of the prefix co- (together) and agere (to drive, lead, act), a prolific root from Proto-Indo-European h₂eǵ- (to drive). The literal sense of 'driving together' evolved into the figurative meaning of 'forcing agreement by argument', implying an idea so powerful it compels the mind to assent. By adding the adverbial suffix '-ly', of Germanic origin, the word formally denotes the manner of presenting an argument: in a compelling, forceful, and logically irresistible way.

Structure: cogent (compelling) + ly (adverb suffix) - cogent: From Latin cogent- (stem of cogens, present participle of cogere 'to compel, drive together'), from co- (together) + agere (to drive, act). Functions as the adjective root. - ly: From Old English -līc (having the form or body of), an adverbial suffix forming adverbs from adjectives.