D defs.my
Entry 1 sense Webster, 1913

Rocket scientist

/räk'-ət sī'-ən-tĭst/ · Rock·et sci·en·tist · IPA /ˌɹɑkət ˈsaɪəntəst/
01 n. a very intelligent person; -- used mostly in the phrases: “you don't have to be a rocket scientist to . . .” and “it doesn't take a rocket …
  1. 1.
    a very intelligent person; -- used mostly in the phrases: “you don't have to be a rocket scientist to . . .” and “it doesn't take a rocket scientist to . . .”, meaning that the subject that follows is easy to understand.