Idiom: Take a hike
Meaning: Leave, go away
Situation: Natalia is standing outside a restaurant waiting for a friend. Bob, who is wearing tight pants and many gold chains, walks up to her...
Bob: Hi, beautiful! How about giving me your phone number?
Natalia: Oh, I have a boyfriend. I can't.
Bob: Don't worry; I won't tell him!
Natalia: Take a hike!
"Take a hike" can be considered rude, but is also very direct.