WordReference Random House Unabridged Dictionary of American English © 2020
101  (wunō wun),USA pronunciation adj. 
  • Informal Termscomprising the introductory material in or as if in a course of study (used postpositively): Economics 101;
    Life 101;
    It's Jungle 101 on a trip up the Amazon.
    • 1985–90

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