PTS Pali-English dictionary - The Pali Text Society's Pali-English dictionary
Niviss
Niviss,a-vādin (adj.-n.) [nivissa (ger.of nivisati)+vādin] “speaking in the manner of being settled or sure,” a dogmatist Sn.910,913,expld at Nd1 326 as “sassato loko idam eva saccaṁ,mogham aññan ti”; at SnA 560 as “jānāmi passāmi tath’eva etan ti.” (Page 372)