mum


mum (http://definr.com/mum)

     adj : failing to speak or communicate etc when expected to; "the
           witness remained silent" [syn: silent]
     n 1: of China [syn: florist's chrysanthemum, {florists'
          chrysanthemum}, Dendranthema grandifloruom, {Chrysanthemum
          morifolium}]
     2: informal terms for a mother [syn: ma, mama, mamma, mom,
         momma, mommy, mammy, mummy, mater]
     3: secrecy; "mum's the word"