apodictic
adjective
apo·dic·tic ˌa-pə-ˈdik-tik 
variants or less commonly apodeictic
ˌa-pə-ˈdīk-tik
: expressing or of the nature of necessary truth or absolute certainty
apodictically
ˌa-pə-ˈdīk-ti-k(ə-)lē
adverb 
Did you know?
Apodictic is a word for those who are confident about that of which they speak. It's a handy word that can describe a conclusive concept, a conclusive person, or even that conclusive person's conclusive remarks. A well-known close relative of apodictic is paradigm ("an outstandingly clear or typical example"); both words are built on Greek deiknynai, meaning "to show." More distant relatives (from Latin dicere, a relative of deiknynai that means "to say") include diction, dictate, edict, and predict.
Word History
Etymology
Latin apodicticus, from Greek apodeiktikos, from apodeiknynai to demonstrate, from apo- + deiknynai to show — more at diction
First Known Use
circa 1645, in the meaning defined above