MJ

See also: mj, mJ, and mj.

Translingual

Symbol

MJ

1. (metrology) Symbol for the megajoule, an SI unit of work or energy equal to 10⁶ joules.

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English

Noun

MJ (uncountable)

1. (slang) Initialism of Mary Jane; marijuana.
2. Initialism of mahjong.
   • 2006, Judy Yung, Gordon H. Chang, H. Mark Lai, Chinese American voices: from the gold rush to the present ...^[1], ISBN 0520243102, 9780520243101 , page 283:

     Then when my sister was old enough, my mother taught the three of us how to play MJ [mah-jongg].