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1. Chem (of water) impairing the formation of a lather by soap
2. (of alcoholic drink) being a spirit rather than a wine, beer, etc.
3. (of a drug such as heroin, morphine, or cocaine) highly addictive
4. Physics (of radiation, such as gamma rays and X-rays) having high energy and the ability to penetrate solids
5. Physics (of a vacuum) almost complete
6. Chiefly US (of goods) durable
7. politically extreme
8. Brit a roadway across a foreshore
Quality of a material that is compact, solid, and difficult to deform.