Nickname of
Joseph Estrada, actor and former President of the
Philippines. A common method of mangling/slangifying words in
Filipino culture involves swapping syllables or inverting the words. "Erap" was derived from "
Pare," which is slang for a male "
buddy" or "
pal" (further derived from the Spanish
compadre).
This meaning is somewhat ironic at this point in history. A buddy is someone who is loyal and will help you out. When visiting San Juan, a town he was once mayor of, then-President Estrada encountered a disheveled man, who was obviously faring very poorly. Estrada recognized the man as one of his security guards, 15 years ago. After conversing with the man for a few minutes, Estrada slipped the man some money.
The ironic part is that "buddy" is often used superficially; a person will call you buddy if he or she needs something from you. The allegations that Estrada was involved in racketeering and embezzling (which led to his ousting), while posing as champion of the poor, is reflective of this other meaning.
His nickname stuck long before he became President, and it is quite eerie as to how accurate it is.