In American legal jargon, lascivious is a semi-technical term indicating immoral sexual actions and in certain cases, words or thoughts.
The legal definition of the term varies greatly across jurisdictions, and has evolved significantly over time, reflective of current moral values as they relate to sexuality.
[2] In 2016, Governor Rick Scott of Florida signed into law SB 0498 which no longer makes "lascivious cohabitation" a crime.
[3] In 2023, Governor Gretchen Whitmer of Michigan signed into law SB 56 which no longer makes "lewd or lascivious cohabitation" a crime.
It thus appears that the term 'indecent exposure' lacks a 'commonly understood meaning', when considered with respect to parts of the body other than the genitalia.