• (n.) The material of which a plug or stopple is made. • (n.) The act of stopping with a plug. • (p. pr. & vb. n.) of Plug
Printing problem when ink fills in around halftone dots, causing a loss of shadow detail. 
(of well) the process setting cement, or other plug in a well in order to make it safe, from any blow-out and cross flow or environmental impact;
Plug'ging noun 1. The act of stopping with a plug. 2. The material of which a plug or stopple is made. 
Act or process of stopping the flow of water, oil, or gas into or out of a formation through a borehole or well penetrating that formation.