/mus"teuhrd/ , n.
1. a pungent powder or paste prepared from the seed of the mustard plant, used as a food seasoning or condiment, and medicinally in plasters, poultices, etc.
2. any of various acrid or pungent plants, esp. of the genus Brassica, as B. juncea (leaf mustard) , the leaves of which are used for food and is the chief source of commercial mustard, and Sinapis alba (white mustard) . Cf. mustard family .
3. See nitrogen mustard .
4. cut the mustard , Slang. to reach or surpass the desired standard of performance: a pitcher who cuts the mustard with his fastball.
[ 1300-50; ME moustarde a relish orig. made of mustard seed and must, equiv. to moust MUST 2 + -arde -ARD ]