You’ve almost certainly met makebates — though you probably don’t know them by that name — people whose chief aim or pleasure is to spread discord and disharmony. Sir Walter Scott was a great user of this word:
Elsewhere he may be an useful and profitable member of the commonweal — here he is but a makebate, and a stumbling-block of offence.
The Abbot, by Sir Walter Scott, 1820.
Somebody who is a makebate is clearly making a bate. The second half survives today in abate and debate; it’s from Latin battere, to beat or fight (the first sense of debate in English in medieval times was to quarrel or battle). As a noun, bate described discord that was severe enough to result in a fight.
British readers might think they recognise in this another form of bate, a fit of rage or bad temper, an example of which appeared in the Daily Mail in January 2004: “Shrieking with simulated frustration, Clarkson flew into a bate, picked up a hammer and smashed his desktop to smithereens.” But the evidence suggests that this derives from a nineteenth-century respelling of the verb bait, to persecute a person with persistent attacks, so that a person was said to be in a bate as a result of being baited.
Among the other senses of bate, one in particular is known to falconers. A hawk that beats its wings in agitation and flutters off the perch is said to bate. This is ultimately also from Latin battere, but directly from the intermediate French batre, to beat, linked to the verb to batter.