Andrew Price

Andrew Price is a teenager and one of the main characters in the novel. He is initially the best friend of Fats, a frendship which begins to break up by the end of the novel as they both realise that they don't have as much in common as they thought. Andrew suffers from a potentially-lethal peanut allergy, hence his nickname "Peanut". His main nickname, "Arf", is almost certainly from the expression "half-price"; it is also possible that his middle name, if he has one (we're not told), is Arthur.

Etymology
"Andrew" is an Anglicisation of the Greek name Ανδρέας "Andreas", which in turn is derived from the Greek ἀνδρός "andros" meaning "man" (specifically, a male human); it thus means "manly" or "virile", hence is a cognate of Fergus.