"Mahabone" is a secret word that means "the Grand Lodge door opened." It is whispered into a candidate's ear when they are entering the third degree of Masonry by means of the Lion's Grip.
According to Masonic scholars, the origin of the word "mahabone" traces back to 967 B.C. A mason called Hiram Abiff claimed he knew the temple's secret. Abiff was then kidnapped by three people who threatened to murder him if he did not reveal the secret. He was killed after refusing to talk.
On finding out about Abiff's death, King Solomon instructed a group of masons to find Abiff's body and return the temple's secret, but the body was never found. The King decided to establish a new secret, which is believed to be mahabone.