The Collaborative International Dictionary of English v.0.48:

R and D \R and D\ ([aum]r`[a^]n*d[=e]"), n. [research and
   development.]
   research and development; -- used mostly to refer to the
   division of a corporation responsible for performing research
   and developing new products; -- a commonly used abbreviation.

   Syn: R&D. [PJC]