What prefix signifies something that is beyond normal?

The prefix that signifies something that is beyond normal is "ultra-." This prefix is derived from the Latin word "ultra," meaning "beyond" or "excessive." In medical terminology, it is often used to describe conditions or phenomena that exceed typical limits, such as "ultrasonic" (beyond the range of human hearing) or "ultrahigh" (exceedingly high levels). This prefix effectively communicates that the subject matter relates to an intensity or degree that surpasses the normal or expected.

The other prefixes, while useful in different contexts, do not carry the same meaning. "Abdomin-" relates specifically to the abdomen, "trans-" often implies across or through, and "tachy-" usually denotes speed, particularly an increased heart rate. These prefixes define different attributes or conditions but do not specifically convey the idea of surpassing normal limits like "ultra-" does.