Hudud means limits. It refers to the limits or bounds of acceptable behaviour and the punishments for serious crimes.
Hudud (Arabic, also transliterated hadud, hudood; singular hadd, حد, literal meaning "limit", or "restriction") is the word often used in Islamic literature for the bounds of acceptable behaviour and the punishments for serious crimes. In Islamic law or Sharia, hudud usually refers to the class of punishments that are fixed for certain crimes that are considered to be "claims of God." They include theft, fornication and adultery (zina), consumption of alcohol or other intoxicants (khamr), and apostasy (see apostasy in Islam).