bush vetch: European purple-flowered with slender stems; occurs as a weed in hedges
vetch: any of various climbing plants of the genus Vicia having pinnately compound leaves that terminate in tendrils and small variously colored flowers; includes valuable forage and soil-building plants
reverse osmosis: (chemistry) a method of producing pure water; a solvent passes through a semipermeable membrane in a direction opposite to that for natural osmosis when it is subjected to a hydrostatic pressure greater than the osmotic pressure