Not regular; not according to common form or rules; as an irregular building or fortification.

Not according to established principles or customs; deviating from usage; as the irregular proceedings of a legislative body.

Not conformable to nature or the usual operation of natural laws; as an irregular action of the heart and arteries.

Not according to the rules of art; immethodical; as irregular verse; an irregular discourse.

Not in conformity to laws, human or divine; deviating from the rules of moral rectitude; vicious; as irregular conduct or propensities.

Not straight; as an irregular line or course.

Not uniform; as irregular motion.

In grammar, an irregular noun or verb is one which deviates from the common rules in its inflections. [RREGULAR.

A soldier not in regular service.