positive definite adjective Trending Now: More Trending: lowlife kakistocracy slimeball salacious oligarch SEE ALL See What's Trending Now See More Trending Words What's Trending Now More Trending Words lowlife 'a person of low moral character' kakistocracy 'government by the worst people' slimeball 'a morally repulsive or odious person' salacious 'arousing or appealing to sexual desire' oligarch 'government in which a small group exercises control' SEE ALL Time Traveler! Explore the year a word first appeared Definition of positive definite 1 : having a positive value for all values of the constituent variables positive definite quadratic forms 2 of a matrix : having the characteristic roots real and positive First Known Use of positive definite 1904 See Words from the same year NEW! Time Traveler Seen and Heard What made you want to look up positive definite? Please tell us where you read or heard it (including the quote, if possible). show hide