irregular >> ɪˈrɛɡjʊlə
Definition: [adjective] not even or balanced in shape or arrangement.
Example: his strong, irregular features
Definition: [adjective] contrary to the rules or to that which is normal or established.
Example: their involvement in irregular financial dealings
Definition: [adjective] (of a verb or other word) having inflections that do not conform to the usual rules.
Definition: [noun] a member of an irregular military force.
Definition: [noun] an imperfect piece of merchandise sold at a reduced price.