Pronunciation: (lag'ing),[key] —n. the act of falling or staying behind.
—adj. lingering; loitering; slow and dragging: lagging steps.
Pronunciation: (lag'ing),[key] —n. 1. the act of covering a boiler, oil tank, etc., with heat-insulating material.
2. the covering formed.
3. the material used.
4. a number of boards or the like joined together side by side to line an excavation.
5. Masonry.a number of lags, taken as a whole.