1) a putting to rest
1a) calming of the winds
2) a resting place
2a) metaphorically the heavenly blessedness in which God dwells, and of which he has promised to make persevering believers in Christ partakers after the toils and trials of life on earth are ended
Part of Speech: noun feminine
Citing in TDNT: 3:628, 419
From G2664; reposing down, that is, (by Hebraism) abode: - rest.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root κατάπαυσις; click on the second column to search for that grammatical form of the root κατάπαυσις; click on the third column to search for that word and grammatical form; click on the total to search for the root κατάπαυσις.