(1):

(n.) The act of resping or breathing; the act of taking in and giving out air; the aggregate of those processes bu which oxygen is introduced into the system, and carbon dioxide, or carbonic acid, removed.

(2):

(n.) Interval; intermission.

(3):

(n.) Relief from toil or suffering: rest.

(4):

(n.) The act of respiring or breathing again, or catching one's breath.