"hut built by miners over a mine shaft," to store their equipment, etc., 1650s, from some source akin to Dutch kouw, German kaue in the same sense, from West Germanic *kauja-, an early borrowing of Latin cavea "hollow," from cavus "a hollow" (from PIE root *keue- "to swell," also "vault, hole").
"The fiery cross which in old times formed the rallying symbol in the Highlands of Scotland in any sudden emergency," Gaelic cranntara, cranntaraidh, also (by influence of crois "cross") croistara, croistaraidh, literally "the beam or cross of reproach," from crann "a beam, a shaft" (see crane (n.)) + tair "reproach, disgrace." "[S]o called because neglect of the symbol implied infamy" [Century Dictionary].
mid-13c., "to end at, to border on, touch at the end," from Old French aboter, abuter "join end to end, touch with an end" (13c.), and abouter "join end to end," from à "to" (see ad-) + boter, bouter "to strike, push," from a Germanic source, from Proto-Germanic *buttan, from PIE root *bhau- "to strike." Compare butt (v.). Related: Abutted; abutting.