- a mineral, nickel sulfide, NiS, occurring in slender, bronze-colored crystals: a minor ore of nickel.
- a follower of William Miller, a U.S. preacher who taught that the Second Advent of Christ and the beginning of the millennium were to occur in 1843.
- a yellow mineral consisting of nickel sulphide in hexagonal crystalline form: a minor ore of nickel. Formula: NiS
