Definition of M and B in US English:

M and B

(also M. & B., M & B)


  • A pharmaceutical preparation originally marketed by the firm May and Baker, especially "M & B 693"noun the antibiotic sulphapyridine. Also, with distinguishing number: any of other pharmaceutical preparations manufactured by May and Baker. [A trademark in the United Kingdom. A symbol incorporating the letters M and B was registered as a trademark in 1935 (trademarks Jrnl. (1935) 30 Oct. 1349).]


1930s; earliest use found in The Lancet. From the initial letters of the May and Baker Co Ltd, pharmaceutical manufacturers.


M and B

/ɛm (ə)n(d) biː/