unreal

UK: ʌnˈrɪəl | US: ʌnˈriːəl

Definition
  1. adj. not real or genuine; imaginary or artificial

  2. adj. (informal) incredibly good or impressive; unbelievable

Structure
un <not>real <actual, true>
Etymology

The word "unreal" combines the Old English prefix "un-" (meaning "not") with the adjective "real," derived from Latin "realis" (relating to things, from "res" meaning "thing"). The prefix "un-" has been used in English since the early medieval period to negate adjectives, while "real" entered Middle English via Old French. Together, they form a straightforward negation, originally meaning "not actual," but in modern slang, it can ironically mean "astonishingly good," showcasing semantic inversion.

Examples
  1. The special effects in the movie made the scenes look unreal.

  2. Her talent is so extraordinary, it’s almost unreal.

  3. The idea of time travel still feels unreal to many scientists.

  4. He described the concert as an unreal experience.

  5. The counterfeit bills were easily identified as unreal.