flog

From Middle English *floggen (suggested by flogge (“hammer, sledge”), from Old English *floggian, a stem variant of Proto-Germanic *flukkōną (“to beat”), itself a secondary zero-grade iterative with unetymological -u-, derived from *flōkaną.

The original zero-grade iterative *flakkōną had been misinterpreted as an o-grade. See flack (“to beat”), also as a dialectal noun "a blow, slap". Cognate with Scots flog (“a blow, stripe, flogging”, noun), Scots flog (“thin strip of wood”), Norwegian flak (“a piece torn off, strip”).

Alternatively, a back-formation from flogger, from Low German flogger (“a flail”).

Blend of fake +‎ blog.