quiet and peaceable: a settled person who lives calmly and causes no trouble
This adjective describes a person who is settled and at peace, the opposite of a troublemaker. It belongs to a small family of Hebrew words built on the idea of coming to rest: the related verb can mean to be at rest or to grow calm, and a closely related noun names a moment, the brief instant in which something settles into stillness.
The word appears only once in the whole Hebrew Bible, in Psalm 35:20. There the writer contrasts violent schemers with "the quiet ones of the land," the peaceable people those schemers target with their lies. The picture is of ordinary, settled folk who keep to themselves and wish no one harm, set against the people plotting against them.
Because the word is so rare, its exact shade has to be filled in from that one verse and from its close relatives. The sense that best fits is peaceable and undisturbed: people minding their own business who want only to live in peace, gentle enough that the wicked treat them as easy prey.