- rheologyThe branch of physics that studies the deformation and flow of matter.
- rhyoliteAn igneous, volcanic (extrusive) rock, of felsic composition, with aphanitic to porphyritic texture.
- rheostatAn electrical resistor with two terminals, the resistance of which can be varied continuously by moving a knob or slider to regulate the flow of an electric current.
- arheicHaving no drainage channels due to lack of rainfall.
- endorheicOf a basin or lake: having no outflow to an external body of water such as a river or ocean, and only losing water through evaporation or seepage into the ground.
- exorheicExternally drained; having one or more outlets.
- rheo-flow, current