1. Grossly irreverent toward what is held to be sacred.
2. Characterized by profanity or cursing.
3. Expressing, or involving, disrespect for God or sacred things; to speak evil of: Henry's blasphemous acts and statements were an indignity or irreverence displayed toward divine powers or their representatives, or toward the king, or toward something sacred; such as, a temple or church.

In Mosaic law, blasphemous statements were capital offenses (Leviticus 24:16); including curses, profanity, disrespect, or impious behavior.