Main Entry: oa·kum

Pronunciation: \ˈō-kəm\

Function: noun

Etymology: Middle English okum, from Old English ācumba tow, from ā- (separative & perfective prefix) + -cumba (akin to Old English camb comb) — more at abide

Date: 15th century

: loosely twisted hemp or jute fiber impregnated with tar or a tar derivative and used in caulking seams and packing joints