Middle English word betch comes from Proto-Indo-European *bʰog-

Detailed word origin of betch

Dictionary entry	Language	Definition
*bʰog-	Proto-Indo-European (ine-pro)	flowing water, flowing water, brook, stream, flowing water, stream
*bakjaz	Proto-Germanic (gem-pro)
becc	Old English (ang)
becck	Middle English (enm)

Words with the same origin as betch