- irreflective
- irreflective relation
- irreflexive
- irreflexivity
- irrefutability
- irrefutable
- irrefutable formula
- irrefutable proposition
- irregular
- irregular anagalactic nebula
- irregular birational transformation
- irregular block
- irregular bone
- irregular boundary point
- irregular chip
- irregular close packing
- irregular cluster
- irregular cluster of galaxies
- irregular coagulation
- irregular continued fraction
- irregular cusp
- irregular decomposition
- irregular determinant
- irregular distribution
- irregular dominance