Lookups on Merriam-Webster spiked on February 22, 2011.
During a televised speech, Libyan leader Muammar el-Qaddafi reacted to the uprising in his country by declaring, "I am a fighter, a revolutionary from tents. I will die as a martyr at the end."
Martyr means a person who sacrifices his or her life for religion or principle; by extension, it has also come to mean "victim."
It comes from the Greek word for "witness," the term used for early Christians who were put to death because they would not renounce their faith. (In the book of Acts, Jesus refers to his followers as "witnesses.")