- transitive verb; slang
- the application of a heated object to a substance, causing this substance to smolder and produce smoke, which is then inhaled
Hot-knifing a controlled substance is often recommended where a robust source of flame cannot be had. For example, hashish is difficult to smoke without a lasting source of flame or extreme heat. Using matches to smoke hashish is inadvisable and frustrating, as it often results in burned fingers. Butane lighters can be even more hazardous, given the pressurized gas they contain.
Most users do not have proper hookahs (water pipes that are designed to accomodate hot rocks or coals as a source of combustion). Enter the practice of hot-knifing: here, an object that has a high ignition point (like . . . say . . . a knife) is placed on or near a source of extreme heat (a campfire, a gas stove or the element of an electric range, etc.) and then applied to whatever is needing to be smoked (hash is only one of a wide variety of psychoactive substances).