Vito refers to Sollozzo as an infidel right at the end of his conversation with Tom and Sonny about the next day's meeting with Sollozzo when they are discussing why Sollozzo wants to meet with Vito. He asks Tom what time he is to meet with this infidel.
Again, infidel is an unflattering term that is usually used by religious people to refer to other religious people, in a pejorative sense.
"Generosity. That was my first mistake." "Experience must be our only guide; reason may mislead us." "Instagram is Twitter for people who can't read."
