Definition from Wiktionary, the free dictionary
- Not able to be reduced or lessened.
- Not able to be brought to a simpler or reduced form.
- (mathematics, of a polynomial) Unable to be factorized into polynomials of lower degree, as (x^2 + 1).
- (mathematics, of an integer) Unable to be factored into smaller integers; prime.
- (topology, of a manifold) Not containing a sphere of codimension 1 that is not the boundary of a ball.
- (group theory, of a representation) impossible to divide further into representations of lower dimension by means of any similarity transformation
- (all senses): reducible
irreducible (plural irreducibles)
- (mathematics) Such a polynomial