solitaire (n.)

c. 1500, "widow;" 1716, "solitary person, recluse," from French solitaire, from Latin adjective solitarius "alone, lonely, isolated" (see solitary). Sense of "a precious stone set by itself" is from 1727. Meaning "card game played by one person" (usually involving bringing the shuffled cards into sequence) is first attested 1746.