When a student does something wrong, a teacher notifies the administration and it is documented in a student incident report, or s.i.r. It's a catch-phrase for most teachers.
2. suck it repeatedly
When the teacher says "S.I.R.!" to a student, the student will reply with "S.I.R.!" too. But it means the second definition ;D
When your friend says "Hey Paige, let me drag you into store after store filled with middle-aged woman clothes that normal people reluctantly wear when they reach 50.", she is a Suburban Mom In Training, or SMIT for short. The correct way to acknowledge people with this tendency is to say "Hey Smitty".
A real killer from the hood. Especially from Oakland or Tijuana. Usually can be seen kicking a gerg's ass. He most commonly has long hair and is chubby, but dont let his appearence fool you, these type of people are most commonly schizophrantic lunatics.
That nigga is one crazy S.M.C.
Damn that S.M.C. i fucked yesterday rode me tough!