Appease, v. t. [imp. & p. p. Appealed; p. pr. & vb. n. Appeasing.]
Etymology: [OE. apesen, apaisen, OF. apaisier, apaissier, F. apaiser, fr. a (L. ad) + OF. pais peace, F. paix, fr. L. pax, pacis. See Peace.]
To make quiet; to calm; to reduce to a state of peace; to still; to pacify; to dispel (anger or hatred); as, to appease the tumult of the ocean, or of the passions; to appease hunger or thirst.
Syn. -- To pacify; quiet; conciliate; propitiate; assuage; compose; calm; allay; hush; soothe; tranquilize.
Shades of meaning
Fernald has no entry of its own for appease; he lists it under allay.
Where he writes about it:
Pacify, directly from the Latin, and appease, from the Latin through the French, signify to bring to peace; to mollify is to soften; to calm, quiet, or tranquilize is to make still; compose, to place together, unite, adjust to a calm and settled condition; to soothe (originally to assent to, humor) is to bring to pleased quietude. — from allay
We allay excitement, appease a tumult, calm agitation, compose our feelings or countenance, pacify the quarrelsome, quiet the boisterous or clamorous, soothe grief or distress. — from allay