debalancer

plural debalancers

1. Something that upsets or destroys the balance.

   1 more example

   Then there were the triffids patiently waiting. I could see hundreds of them in a dark green hedge beyond the fence. There must be research - some natural enemy, some poison, a debalancer of some kind, something must be found to deal with them; there must be relief from other work for that - and soon.

   1951, John Wyndham, The Day of the Triffids, Harmondsworth: Penguin Books, published 1954, page 259