Peaceable, a.
Etymology: [OE. peisible, F. paisible.]
Begin in or at peace; tranquil; quiet; free from, or not disposed to, war, disorder, or excitement; not quarrelsome. -- Peace"a*ble*ness, n. -- Peace"a*bly, adv.
Syn. -- Peaceful; pacific; tranquil; quiet; mild; undisturbed; serene; still. -- Peaceable, Peaceful. Peaceable describes the state of an individual, nation, etc., in reference to external hostility, attack, etc.; peaceful, in respect to internal disturbance. The former denotes "in the spirit of peace;" latter; "in the possession or enjoyment of peace." A peaceable adjustment of difficulties; a peaceful life, scene.
Shades of meaning
Fernald lists peaceable only as an antonym, under restive.
He lists it without comment; the entries above explain its neighbors.