Leonard was really annoyed by Sheldon's attempting to join his research.
Not only that Leonard thought he didn't need any help but also Leonard's inappropriate and rude behavior of interrupting.
Leonard had nothing but shouting Sheldon away.
hunch: pretty sure about something though you don't have any evidence.
guess: offer your personal opinion but you don't have definite knowledge about it.
stuff: talking about something in general way without mentioning its name.
engage: take part in doing something.
normal: usual, ordinary,