But he had soldiered on, bound by loyalty to Hillary and an implacable sense of duty.
Abandoned its implacable opposition to the International Red Cross.
And so DeMint, an implacable foe of Obamacare, will now get paid to run the organization that helped incubate Obamacare.
unable to be appeased; irreconcilable
Latin im- + placare 'to appease'