ir·reg·u·lar / iˈregyələr/ • adj. 1. not even or balanced in shape or arrangement: her features were too irregular. ∎ occurring at uneven or varying rates or intervals: an irregular heartbeat. ∎ Bot. (of a flower) having the petals differing in size and shape; zygomorphic.2. contrary to the rules or to that which is normal or established: they were questioned about their involvement in irregular financial dealings. ∎ (of troops) not belonging to regular or established army units. ∎ Gram. (of a verb or other word) having inflections that do not conform to the usual rules.• n. (usu. irregulars) 1. a member of an irregular military force.2. an imperfect piece of merchandise sold at a reduced price.DERIVATIVES: ir·reg·u·lar·ly adv.