delay variation; jitter
Technical term in computing and networking for the variation in packet delay.
If the network delay variation is large, the quality of voice calls degrades.
This router has a function to suppress jitter.
Means 'delay' in general; 遅延揺らぎ specifically refers to the variation of delay.
Compound of 遅延 (delay) and 揺らぎ (fluctuation, variation).