In the case of Randall âmispronouncingâ cretin, the American English pronunciation would be kree-tin (Mike), but in British English this would be kre-tuhn (Randallâs). This would be an understandable mistake if Randallâs only ever read the word, or heard someone else pronounce it that way.
We know that Randall is a smart character from both his skillset in MI and his success in MU. More specifically, Johnny makes a point of hounding Sulley for his grades, and then replaced Sulley with Randy. Randy, who was Mikeâs study partner. Randy, who was accepted into MU in the first place. This *would* indicate Randy being particularly well read, despite what his insecurity would lead one to believe.
However, it could also be that Randall knew the word through it being used by someone else.
We also know based off of Randyâs insecurity in contrast to Mike and Sulleyâs blind confidence, that he does not come from a Scaring household. That he needs Mike to point out the way that his camouflage can be of use to him in Scaring, instead of an embarrassment. A prey animalâs defense response instead being a predatorâs method of attack. If he were experienced in the Scaring world, he wouldnât have needed this pointer. Heâs new.
Randall also doesnât look like any other monster we see around MI or MU, and itâs only in MAW that the similarly structured Mr. Crummyham is introduced.
British English is the more globally standardized form people are taught in other countries, as a result of a whole bunch of historical stuff we donât need to get into. All this to say that Randall couldâve very well heard the word said by a parent or relative who learned English in one of the British circles. A world like cretin, very known for being an offensive insult.