rheum (n.) Look up rheum at Dictionary.com
"mucous discharge," late 14c., from Old French reume "a cold" (13c., Modern French rhume), from Latin rheuma, from Greek rheuma "discharge from the body, flux; a stream, current, flood, a flowing," literally "that which flows," from rhein "to flow," from PIE root *sreu- "to flow" (cognates: Sanskrit sravati "flows," srotah "stream;" Avestan thraotah- "stream, river," Old Persian rauta "river;" Greek rheos "a flowing, stream," rhythmos "rhythm," rhytos "fluid, liquid;" Old Irish sruaim, Irish sruth "stream, river;" Welsh ffrwd "stream;" Old Norse straumr, Old English stream, Old High German strom (second element in maelstrom); Lettish strauma "stream, river;" Lithuanian sraveti "to trickle, ooze;" Old Church Slavonic struja "river," o-strovu "island," literally "that which is surrounded by a river;" Polish strumień "brook").