Definition of lagging
: a lag or material used for making lags: as a : material for thermal insulation especially around a cylindrical object b : planking used especially for preventing cave-ins in earthwork or for supporting an arch during construction
First Known Use of lagging
LAGGING Defined for English Language Learners
Definition of lagging for English Language Learners
: a special material that is used to cover something (such as a pipe) to keep it from losing or gaining heat
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