Etymology

From Old French soing ‎(“care; attention”) (compare French soigner ‎(“to treat; to nurse; to look after, take care of”), soigné ‎(“immaculate”)), from Frankish *sunnija ‎(“worry, care, concern”), from Proto-Germanic *sunjō, *sunþijō ‎(“truth, care, responsibility”), from Proto-Indo-European *snt-, *sent- ‎(“being, true”), from *h₁es-, *h₁esmi- ‎(“to be”).