nadir /nāˈdēr, nadˈēr or -dər/

1. The point of the heavens diametrically opposite to the zenith
2. The lowest point of anything, esp an emotional state

• keep something quiet
• keep something up one's sleeve
• keep step
• keep tabs on
• keep the ball rolling
• keep the field
• keep the flag flying
• keep the house
• keep the peace
• keep the pot a-boiling
• keep the pot boiling
• keep the ring
• keep the weather of
• keep the wolf from the door
• keep time
• keep to
• keep to oneself
• keep track of
• keep under
• keep under wraps
• keep up
• keep up appearances
• keep up with the Joneses
• keep warm
• keep wicket