Lemon Test: A three-part test articulated by the Supreme Court in Lemon v Kurtzman for laws dealing with religious establishment issues; To pass this test, a statute must have a secular legislative purpose, its principal or primary effect must be one that neither advances nor inhibits religion, and it must not foster an excessive government entanglement with religion.
School Prayer: The term for state-sanctioned or mandatory prayer by students in public schools. Depending on the country and the type of school, state-sponsored prayer may be required, permitted, or prohibited.
Establishment Clause: A part of the First Amendment stating that 'Congress shall make no law respecting an establishment of religion.' This clause not only forbids the government from establishing an official religion but also prohibits government actions that unduly favor one religion over another.