Pronunciation: (in"vu-kā'shun),[key] —n. 1. the act of invoking or calling upon a deity, spirit, etc., for aid, protection, inspiration, or the like; supplication.
2. any petitioning or supplication for help or aid.
3. a form of prayer invoking God's presence, esp. one said at the beginning of a religious service or public ceremony.
4. an entreaty for aid and guidance from a Muse, deity, etc., at the beginning of an epic or epiclike poem.
5. the act of calling upon a spirit by incantation.
6. the magic formula used to conjure up a spirit; incantation.
7. the act of calling upon or referring to something, as a concept or document, for support and justification in a particular circumstance.
8. the enforcing or use of a legal or moral precept or right.