The scent left behind by perfume, usually after the subject has passed.
Man: Her perfume came on a bit strong, but the sillage was perfect.
1. The action of passing by someone you are deeply fond of without making any sign as to recognizing their existence.
2. The act of pretending not to know someone you've slept with/had intimate relations with the night before.
Dude, just go simea. Pretend not to know her.