Someone who's mum has nothing to say, especially on a particular subject. If you agree to keep someone's secret, you could tell them, "Mum's the word!"
p. pr. & vb. n.
of Mumm
Usage Examples
Mumming, Mumming, umming, Mumming, Myumming, M7umming, M8umming, Miumming, Mjumming, Mymming, M7mming, M8mming, Mimming, Mjmming, Muymming, Mu7mming, Mu8mming, Muimming, Mujmming, Munmming, Mujmming, Mukmming, Mu,mming, Mu mming, Munming, Mujming, Mukming, Mu,ming, Mu ming, Mumnming, Mumjming, Mumkming, Mum,ming, Mum ming, Mumnming, Mumjming, Mumkming, Mum,ming, Mum ming, Mumning, Mumjing, Mumking, Mum,ing, Mum ing, Mummning, Mummjing, Mummking, Mumm,ing, Mumm ing, Mummuing, Mumm8ing, Mumm9ing, Mummoing, Mummjing, Mummking, Mummung, Mumm8ng, Mumm9ng, Mummong, Mummjng, Mummkng, Mummiung, Mummi8ng, Mummi9ng, Mummiong, Mummijng, Mummikng, Mummibng, Mummihng, Mummijng, Mummimng, Mummi ng, Mummibg, Mummihg, Mummijg, Mummimg, Mummi g, Mumminbg, Mumminhg, Mumminjg, Mumminmg, Mummin g, Mumminfg, Mummintg, Mumminyg, Mumminhg, Mumminbg, Mumminvg, Mumminf, Mummint, Mumminy, Mumminh, Mumminb, Mumminv, Mummingf, Mummingt, Mummingy, Mummingh, Mummingb, Mummingv.