'sententious' originates from Latin, specifically the word 'sententiosus,' where 'sententia' meant 'opinion' or 'judgment'.

'sententious' changed from the Late Latin word 'sententiosus' and was adopted into English (via literary Latin/early modern usage) to become the modern English word 'sententious'.

Initially, it meant 'full of opinions' or 'given to expressing judgments'; over time it acquired senses of 'terse and aphoristic' and 'moralizing/preachy' in modern usage.