- sincerity (n.)
- 1540s, from Middle French sincérité (early 16c.), from Latin sinceritatem (nominative sinceritas), from sincerus "sound, pure, whole," perhaps originally "of one growth" (i.e. "not hybrid, unmixed"), from sem-, sin- "one" + root of crescere "to grow" (see crescent). Ground sense is of "that which is not falsified."