1. A covered walk with an open colonnade on one side, running along the walls of buildings that face a quadrangle: "The royal family lived for generations in a cloister and enjoyed their enclosed gardens that are surrounded by covered walkways."
2. A place; especially, a monastery or a convent that is devoted to religious seclusion: "She spent most of her life in a cloister as a nun."

1. To surround with a cloister, as of a garden: "The family moved to a new residence that was cloistered with beautiful gardens."
2. To seclude from the world in or as if in a cloister: "Just about every working day, she was cloistering herself in her office because she had so much work to do."