(1) Muharram is the first month of the Islamic Calendar. This month is considered a month of mourning by the Shia (and many Sunni) Muslims due to the murder of the Grandson of Prophet Muhammed (PBUH&HP), Imam Hussain (PBUH).
(2) Muharram can mean 'made forbidden'.

Muharram is so-called because it was the main month designated by the pre-Islam Arabs as a month where war was forbidden. They didn't usually follow their own rules and they even made an agreement where they would observe the law on year and the