The American Heritage® Dictionary of the English Language, 4th Edition
n. Adherence to or belief in established forms, especially belief in organized religion.
n. Use of public institutions for the care of people who are physically or mentally disabled, criminally delinquent, or incapable of independent living.
n. Adherence to the established religion, or to established codes of conduct
n. The use of public institutions in health care and social services
The Century Dictionary and Cyclopedia
n. The character of being institutional; in theology, the spirit which lays great emphasis on the institutions of religion.
Word Usage
"Christianity, as opposed to institutionalism, is gaining ground, Individual religious experience as opposed to external authority is becoming "The impregnable rock" of faith."