`Lascivious` is a word synonymous with lustful or lewd or unruly. == Legal usage == In American legal jargon, lascivious is a semi-technical term indicating immoral sexual thoughts or actions. It is often used in the legal description of criminal acts in which some sort of sexual activity is prohibited to differentiate that activity from `innoc...... Found on http://en.wikipedia.org/wiki/Lascivious