That's a temporary system stall when some critical part of the system is overloaded or blocked, usually the disk.

Or an out-of-memory condition, the system recovers when the OOM killer has killed a random process. If you were lucky that process was your game hogging ressources and when it went away the system recovered.

And for impressive German words? "Systemaufstauung mit urplötzlicher Lösung" (system bottleneck with sudden resolving), "Speicherüberlastung" (memory overload) or "Prozessabmurkser" (process terminator).

Note that I invented these words (oder auf gut Deutsch, ich habe mir diese Wörter aus den Fingern gesaugt).