Manco

In the English-dubbed version of the film, Eastwood's character is said to "go by the name of 'Manco." "Manco" is a Portuguese/Spanish word that means "one-armed" and "lame of one hand"; Eastwood's character performs nearly all actions using only his left hand, to leave free his right hand, with which he draws. His behavior thus bears a joking resemblance to that of a one-armed man.
The Italian equivalent of the word "manco," which serves as Eastwood's character's sobriquet, is "monco." In many written sources, the Man with No Name is called Monco, either due to the Italian form or to faulty spelling. In any case, the dubbed voices of the film's characters seemingly pronounce "Manco" when they refer to him.