conclusively
UK: kənˈkluːsɪvli | US: kənˈkluːsɪvli
adv. in a decisive or final manner, leaving no doubt
adv. (logic) in a way that logically follows from the premises
The root "clus" (from Latin claudere, "to shut") forms the core of "conclusively," combined with the prefix "con-" (intensifying "together") and the suffix "-ive" (forming adjectives). The addition of "-ly" converts it into an adverb. Historically, the word evolved from Latin conclusivus (final, decisive), reflecting the idea of "shutting together" an argument or proof definitively.
The evidence proved conclusively that the suspect was innocent.
Her argument was presented conclusively, leaving no room for debate.
The study demonstrated conclusively that the treatment was effective.
He spoke conclusively, ending all speculation about his plans.
The data supports the theory conclusively.