A Tick Throw is a specific technique where a player does an attack with little blockstun (like a 2A or 5P), and immediately throwing the opponent afterwards.
This takes advantage of the fact that fast attacks with little blockstun usually have frame advantage. The opponent expects a Frame Trap and decides to block instead of attacking back or jumping out.
A few tick throw examples
Almost all fighting games have a bit of throw protection after blockstun, hitstun, and wakeup. This means that the opponent is invincible to throws even after exiting stun for a few frames (the exact amount varies from game to game). If your tick throw whiffs even though the opponent is clearly in range, then try delaying your throw slightly.
Getting Hit to Avoid Tick Throw
Tick throws usually rely on making the opponent block an attack before throw. If the opponent gets hit instead of blocking, then the throw will miss; they'll still be in throw protection since getting hit has more stun than blocking that same attack.