[uhl-truh] 
| 1. | going beyond what is usual or ordinary; excessive; extreme. |
| 2. | an extremist, as in politics, religion, fashion, etc. |
| 3. | (initial capital letter ) Military. the British code name for intelligence gathered by decrypting German wireless communications enciphered on the Enigma machine during World War II. |
| a prefix occurring originally in loanwords from Latin, with the basic meaning “on the far side of, beyond.” In relation to the base to which it is prefixed, ultra- has the senses “located beyond, on the far side of” (ultramontane; ultraviolet), “carrying to the furthest degree possible, on the fringe of” (ultraleft; ultramodern), “extremely” (ultralight); nouns to which it is added denote, in general, objects, properties, phenomena, etc., that surpass customary norms, or instruments designed to produce or deal with such things (ultramicroscope; ultrasound; ultrastructure). |
| ul·tra (ŭl'trə) adj. Immoderately adhering to a belief, fashion, or course of action; extreme. n. An extremist. [French, from Latin ultrā-, ultra-.] |
ultra- pref.
Beyond; on the other side of: ultraviolet.
Beyond the range, scope, or limit of: ultrasonic.