WordNet sense 1 (an organization founded and united for a specific purpose):

establishment

WordNet sense 2 (a hospital for mentally incompetent or unbalanced person):

asylum, insane asylum, mental home, mental institution, psychiatric hospital, mental hospital

WordNet sense 3 (the act of starting something for the first time; introducing something new):

creation, foundation, initiation, innovation, instauration, introduction, origination, founding