oakum

From Middle English okome, from Old English ācumba (“oakum”, literally “that which has been combed out, off-combings”), a derivative of ācemban (“to comb out”), from Proto-Germanic *uz- + *kambijaną (“to comb”), from Proto-Indo-European *uds-, *ūd- (“out”) + Proto-Indo-European *ǵombʰ-, *ǵembʰ- (“tooth, nail; to pierce, gnaw through”). More at out, comb.

oakum (countable and uncountable, plural oakums)

1. A material, consisting of tarred fibres, used to caulk or pack joints in plumbing, masonry, and wooden shipbuilding.
2. The coarse portion separated from flax or hemp in hackling.

   (Can we find and add a quotation of Knight to this entry?)

• (flax or hemp fibers separated in hackling): tow, hards