1.Definition: (of a surface or shape); not level or flat or symmetrical
"Walking was difficult on the irregular cobblestoned surface"
2.Definition: (of solids) not having clear dimensions that can be measured; volume must be determined with the principle of liquid displacement
3.Definition: (used of the military) not belonging to or engaged in by regular army forces
"Irregular troops", "Irregular warfare"
4.Definition: contrary to rule or accepted order or general practice
"Irregular hiring practices"
5.Definition: deviating from normal expectations; somewhat odd, strange, or abnormal
"Highly irregular behavior"
6.Definition: failing to meet a standard of manufacture due to an imperfection
"An irregular pair of jeans"
7.Definition: independent in behavior or thought
"She led a somewhat irregular private life"
8.Definition: lacking continuity or regularity
"An irregular worker"
9.Definition: not occurring at a regular rate or fixed intervals
"An irregular heartbeat"