What was the Native American chief Geronimo's real name and how did he get this nickname?

Goyathlay (One Who Yawns) was an Apache Medicine Man who was given the nickname Geronimo by the Mexicans (maybe for jumping out of aeroplanes).

At his birth he was given the name Goyahkla, meaning "One Who Yawns", some aged Fort Sill Apaches suggest a name slightly different in pronunciation, with the meaning "intelligent, shrewd, clever." Perhaps this is why the name Gothalay is seen referring to him. It is said that he got the name Geronimo during battle with the Mexicans. Each time he emerged, the Mexicans began to cry out in terror, "Cuidado! Watch out! Geronimo!" Perhaps this was as close as they could come to the choking sounds that composed his name, or perhaps they were calling on Saint Jerome. The Apaches took it up as their battle cry, and Goyahkla became Geronimo.

impurplehawk.com/goyahkla.html webpage no longer exists

Geronimo is Spanish for Jerome, or, if you prefer the Latin, Hieronymus. Geronimo's real name was Goyathlay ("He Who Yawns").

midrangeserver.com/tfh/tfh042902-story07.html no longer exists

There is a slight variation in spelling on some sites. Geronimo, a member of the Bedonkohe Apache tribe, was born in Arizona in 1823. His original name was Goyahkla (He Who Yawns).

http://spartacus-educational.com/WWgeromino.htm