Kindness, n.
Etymology: [From Kind. a.]
1. The state or quality of being kind, in any of its various senses; manifestation of kind feeling or disposition beneficence. I do fear thy nature; It is too full o' the milk of human kindness To catch the nearest way. Shak. Unremembered acts Of kindness and of love. Wordsworth.
2. A kind act; an act of good will; as, to do a great kindness.
Syn. -- Good will; benignity; grace; tenderness; compassion; humanity; clemency; mildness; gentleness; goodness; generosity; beneficence; favor.
Shades of meaning
Fernald has no entry of its own for kindness; he lists it under benevolence, mercy.
Where he writes about it:
Kindness and tenderness are personal; benevolence and charity are general. — from benevolence
Kindness extends to all sentient beings, whether men or animals, in prosperity or in distress. — from benevolence
Humanity is so much kindness and tenderness toward man or beast as it would be inhuman not to have; we say of some act of care or kindness, "common humanity requires it." Generosity is self-forgetful kindness in disposition or action; it includes much besides giving; as, the generosity of forgiveness. — from benevolence
Mercy is the exercise of less severity than one deserves, or in a more extended sense, the granting of kindness or favor beyond what one may rightly claim. — from mercy
Grace is favor, kindness, or blessing shown to the undeserving; forgiveness, mercy, and pardon are exercised toward the ill-deserving. — from mercy