"Mum's the word" has been a popular expression since at least the 17th century;
"Seal up your lips, and give no words but mum." - Shakespeare, Henry VI,
Part II, I, ii.
Mum, with the meaning of silent, is thought to originate in Middle English - the name linguists give to the diverse forms of the English language spoken in England between the Norman invasion in 1066 and about 1470.
The OED defines 'mum' as an inarticulate sound made with closed lips.
News Corp will officially split into two companies June 28(May 24 2013) As expected, News Corp has announced it will officially split its publishing and entertainment businesses on 28 June.
Its board approved the...