An example of something that would be described as lascivious is the leering look that a creepy old man gives young girls at a bar.
Origin of lascivious
- Middle English from Late Latin lascīviōsus from Latin lascīvia lewdness, playfulness from lascīvus lustful, playful las- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition
- From Latin lascÄ«viÅsus, from lascÄ«via (“sportiveness, lustfulness").