To prevent further disagreement in arguments or war by giving to the opposing side an advantage that they have demanded. (Cambridge Dictionary)
To bring to a state of peace or quiet: Calm (Merriam – Webster)
To bring to a state of peace, quiet, ease, calm, or contentment; pacify; soothe: (Dictionary.com)
To satisfy, allay, or relieve; assuage. (Dictionary.com)
To yield or concede to the belligerent demands of (a nation, group, person, etc.) in a conciliatory effort,sometimes at the expense of justice or other principles. (Dictionary.com)
If you try to appease someone, you try to stop them from being angry by giving them what they want. (Collins Dictionary)
Trump, Putin, and the Art of Appeasement.
Rajasthan: Man arrested for sacrificing daughter to appease Allah.