Related Clues:

• It's 'the word'
• Not blabbing
• The word, as suggested by the saying formed by the ends of this puzzle's four longest answers
• On the q.t
• The wallflower is, with nitre etc scattered around
• During break, call back mum
• Reserved - taciturn
• Not saying anything
• Mother - quiet!
• Parent - shtoom
• Disinclined to speak
• Parent (who's kept or is the word!)
• Secretive
• Reserved? It's back in not long ago
• Keep her provided she's a chrysanthemum perhaps