What is Chastity?

Legal Definition
Chastity is sexual behavior of a man or woman that is acceptable to the moral standards and guidelines of their culture, civilization or religion. The term has become closely associated (and is often used interchangeably) with sexual abstinence, especially before marriage and outside marriage.
-- Wikipedia
Legal Definition
That virtue which prevents the unlawful commerce of the sexes.

2. A woman may defend her chastity by killing her assailant. See Self-defence. And even the solicitation of her chastity is indictable in some of the states; 7 Conn. 267; though in England, and perhaps elsewhere, such act is not indictable. 2 Chit. Pr. 478. Words charging a woman with a violation of chastity are actionable in themselves. 2 Conn. 707.
-- Bouviers Law Dictionary
Legal Definition
Purity; continence. That virtue which prevents the unlawful intercourse of the sexes. Also the state of purity or abstinence from unlawful sexual connection. People v. Brown, 71 Hun, 601, 24 N. Y. Supp. 1111; People v. Kehoe, 123 Cal. 224, 55 Pac. 911, 69 Am. St. Bep. 52; State v. Carron, 18 Iowa, 375, 87 Am. Dee, 401. See Chaste character.
-- Black's Law Dictionary
Legal Definition
Sexual righteousness.
-- Ballentine's Law Dictionary