What does lasciviousness mean? And does it speak clearly in the Bible about homsexuality?
Lasciviousness or licentiousness, depending on the translation of your Bible, means being wanton, lewd, or lustful. William Barclay described it as "a love of sin so reckless and so audacious that a man has ceased to care what God or man thinks of his actions." Others, using the word "licentiousness" note that it comes from the word "license." Thus, licentiousness is the attitude that a person gets after repeatedly sinning that he has a license to sin; that is, a right to sin.
In regards to homosexuality, see the Topical Scripture Index on Homosexuality.