What is the meaning of the Latin root ultra?

The meaning of the Latin root ultra is “beyond.” As an English prefix, ultra- describes something that goes past a boundary, limit, or ordinary range.

The root comes directly from Latin ultra, meaning “beyond,” “on the farther side,” or “more than.” English uses it in scientific and everyday words. Ultraviolet refers to radiation beyond the violet end of the visible-light spectrum, while ultrasonic describes sound above the range humans can normally hear.

The meaning can also broaden to “extremely” or “excessively.” For example, ultramodern means extremely modern, and ultranationalist describes an especially intense form of nationalism. This secondary sense developed naturally from the idea of going beyond a normal limit.

A related Latin phrase is plus ultra, meaning “further beyond.” It became the national motto of Spain under Charles V and appears on Spain’s coat of arms. Readers sometimes confuse ultra- with extra-, but both can mean “beyond”; ultra- more strongly suggests surpassing a limit or reaching an extreme.