In Tetris, losing because the stack blocks new pieces from entering the playfield is called topping out.
During normal play, tetrominoes enter from the top of the well and descend toward the floor or the existing stack. Players clear completed horizontal lines, causing blocks above them to fall and creating room for more pieces.
If the accumulated blocks rise high enough to obstruct the entry area, the next piece cannot enter properly. The game then ends, and the player is said to have topped out. The exact visual trigger can vary slightly between Tetris versions, but the term describes the same basic failure condition.
This is different from a soft drop or hard drop, which are ways of controlling a falling piece. “Hold” refers to reserving a piece for later, while a ghost piece is only a visual guide showing where the active piece would land.