From batter +‎ -er.

batterer (plural batterers)

1. One who batters.
   • 1918, Norman Lindsay, The Magic Pudding, Sydney: Angus and Robertson, page 138:

     "If you've been assaulted and battered," said the Mayor, "we shall have to arrest the assaulters and batterers, as well."

2. One who batters their spouse: one who commits domestic violence.
3. (cooking) One who applies batter.
   • 1987, Kerry Cue, Hang On To Your Horses Doovers, page 13:

     "This is serious," replied the potential fish batterer.

• Barrette, barrette, berretta

• (Classical Latin) IPA^(key): /ˈbat.te.rer/, [ˈbät̪ːɛrɛr]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈbat.te.rer/, [ˈbät̪ːerer]

batterer

1. first-person singular imperfect passive subjunctive of battō