late 14c., "not in conformity with Church rules," from Old French irreguler (13c., Modern French irrégulier), from Medieval Latin irregularis, from assimilated form of in- "not, opposite of" (see in- (1)) + Latin regularis (see regular (adj.)). General sense is from late 15c.
irregular (n.)
"a soldier not of the regular army," 1747, from irregular (adj.).
实用例句
1. She was taken to hospital suffering from an irregular heartbeat.
她因心律不齐被送往医院。
来自柯林斯例句
2. At least 17 different irregular units are engaged in the war.
