'hush up' definitions:

Definition of 'hush up'

(from WordNet)
verb
Cover up a misdemeanor, fault, or error; "Let's not whitewash the crimes of Stalin"; "She tried to gloss over her mistakes" [syn: whitewash, gloss over, sleek over, hush up]
verb
Cause to be quiet or not talk; "Please silence the children in the church!" [syn: hush, quieten, silence, still, shut up, hush up] [ant: louden]