keep
US /kiːp/
UK /kiːp/

1.
2.
3.
cause to continue in a specified condition, position, or course of action
:
•
Keep the door closed.
•
The noise kept me awake.
1.
the strongest part of a castle or other fortification, housing the main living quarters and defensive structures.
:
•
The invaders attacked the castle's keep.
•
The ancient keep stood tall against the sky.