1.When someone is a whole lot more up tight than a virgin or their vagina; they are as tight as a shark's gill.
2.When something is very awesome or cool.
1."Bro, how was your date last night?"
"It was horrible, that bitch was shark tight."
"Oh, ouch bro, that sucks..."
2. "Dude, The Dark Knight was sick and shark tight why that movie with the owl wasn't".