Tween

From Wavu Wiki, the 🌊 wavy Tekken wiki

A tween is when one move transitions into another one. It's similar but distinct from a cancel since the second move comes out as if it were started when the first move was, rather than when its input was done. It can also refer to tweening in the normal sense of blending two animations together.

Animation tweening occurs constantly during every game as basic animations such as those for backdash, sidestep, guard, and crouch all blend into the startup animation of any other move. However, tweening is not merely an aesthetic effect in Tekken as it can change the game logic itself by altering hurtboxes, and by changing the visuals it can make it harder for opponents to react to moves.

The term is from animation referring to the frames between two keyframes. These are “in between frames” of animation that were never specifically created but rather generated automatically by an algorithm. As a verb it refers to the transitioning from one keyframe to another.