irregularity.

1. A departure from a usual, even or consistently repeated pattern.

2. A failure to follow an applicable rule, requirement or accepted procedure.

Use it for

Words that belong together

• surface irregularity
• irregularity of timing

On the page

A surface irregularity diverted the reflected light across the otherwise smooth panel.

The irregularity of the timing made the sequence harder to predict.

Usage notes

Primary category: academic / formal. Forms: Singular irregularity; plural irregularities. Often also uncountable. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings. Established modern English lexical item. No separate regional spelling or grammatical inflection entry. Writing functions: definition, comparison, qualification, causal analysis. Disciplines: academic writing, institutional analysis, general research. Commonness: moderately common.