WordNet sense 1 (cease to operate or cause to cease operating):

close, fold

WordNet sense 2 (not receptive):

unreceptive

WordNet sense 3 (secret or hidden; not openly practiced or engaged in or shown or avowed):

covert

WordNet sense 4 ((set theory) of an interval that contains both its endpoints):

closed

WordNet sense 5 (used especially of mouth or eyes):

shut

WordNet sense 6 (bend or lay so that one part covers the other):

turn up, fold up