vitamin d

/V AY1 T AH0 M AH0 N D IY1/
noun
  1. 1

    (biochemistry) Any of a number of fat-soluble vitamins, required for normal bone development and that prevents rickets; can be manufactured in the skin on exposure to sunlight.

  2. 2

    (slang, humorous, somewhat vulgar) A dick (“penis”), especially in a sexual context.