ret (v.) Look up ret at Dictionary.com
"to soak stems of fibrous plants (flax, hemp, jute, etc.) to soften them," mid-15c., probably from Middle Dutch roten (or an unrecorded cognate Old Norse word that is related to Norwegian røyta, Swedish röta, Danish røde); considered to be related to Old English rotian "to rot" (see rot (v.)), but the vowel is difficult.