Old English *bæcce "something baked," from bacan "bake" (see bake (v.)). Batch is to bake as watch (n.) is to wake and match (n.2) "one of a pair" is to make. Extended 1713 to "any quantity produced at one operation."
A bachelor (1850s+)
verb(also bach it) Of a man, to live alone (1860s+)