Collocations for irregularity - noun

serious
minor, slight
a slight irregularity in the surface of the wood

widespread
The newspaper claimed there were widespread irregularities in the election.

accounting, election, electoral, financial, procedural, voting
Investigators found no evidence of financial irregularity.

investigate
detect, report, uncover

occur
Irregularities occur when there is no central control.

irregularity in
Auditors have uncovered serious irregularities in the accounts.