The Collaborative International Dictionary
Skainsmate
Skainsmate \Skains"mate`\, n. [Perhaps originally, a companion in winding thread (see Skein), or a companion in arms, from skain a sword (see Skean).] A messmate; a companion. [Obs.]
Scurvy knave! I am none of his firt-gills; I am none of
his skainsmates.
--Shak.
Wiktionary
skainsmate
n. (context obsolete English) A messmate; a companion.