制度,习俗[C] The institution of slavery was once widespread. 奴隶制度曾经相当普遍。

2.公共团体,机构;公共团体的建筑物[C] A church, school, hospital, asylum, or prison is an institution. 教堂,学校,医院,收容所或监狱皆属公共机构。

3.建立,设立,制定[U] Institution of such schools was geared to these needs. 建立这些学校适应了那些需要。