A temporal distortion is a distortion in the spacetime continuum, a temporal anomaly.
Professor Berlinghoff Rasmussen's time travel pod from the 26th century used temporal distortions to travel through time. (TNG: "A Matter of Time")
The temporal disruptor, a 29th-century weapon, uses temporal distortions to fracture space-time. In the earliest stages, the distortions cause symptoms in humanoids akin to space sickness. (VOY: "Relativity")