The noun plug has 7 senses (first 1 from tagged texts)
1. (15) plug, stopper, stopple -- (blockage consisting of an object designed to fill a hole tightly)
2. chew, chaw, cud, quid, plug, wad -- (a wad of something chewable as tobacco)
3. ballyhoo, hoopla, hype, plug -- (blatant or sensational promotion)
4. spark plug, sparking plug, plug -- (electrical device that fits into the cylinder head of an internal-combustion engine and ignites the gas by means of an electric spark)
5. plug, male plug -- (an electrical device with two or three pins that is inserted in a socket to make an electrical connection)
6. fireplug, fire hydrant, plug -- (an upright hydrant for drawing water to use in fighting a fire)
7. hack, jade, nag, plug -- (an old or over-worked horse)
Overview of verb plug
The verb plug has 4 senses (first 2 from tagged texts)
1. (2) plug, stop up, secure -- (fill or close tightly with or as if with a plug; "plug the hole"; "stop up the leak")
2. (1) plug, plug away -- (persist in working hard; "Students must plug away at this problem")
3. punch, plug -- (deliver a quick blow to; "he punched me in the stomach")
4. plug -- (make a plug for; praise the qualities or in order to sell or promote)