Kindness
Etymology
From Old English "gecynd" and the adjective "kind," rooted in "cynn" (kin, family, natural stock) — the same source as "kin." To be "kind" originally meant to be natural, of one’s kind, behaving as befits kinship. Kindness thus carries a buried claim: that treating others well is treating them as kin, as one’s own.
noun · /KYND-nuhs/
The disposition to treat others with warmth, care, and helpfulness.
What it names
Use it for goodwill that actually reaches another person as care — the small, active gentleness that costs the giver something.
Example
A stranger’s kindness — carrying her bag up three flights — stayed with her for years.
Related idea
Niceness is often about pleasantness and being liked, and can be surface-deep or self-protective; kindness is oriented to the other’s actual good and may deliver a hard truth. Nice avoids friction; kind sometimes accepts it.