^"An unbeliever with respect to a particular religion, especially Christianity or Islam". "Infidel", The American Heritage Dictionary of the English Language, Fourth Edition, Houghton Mifflin Company.
^"Infidel", Random House Unabridged Dictionary, Random House, 2006.
^"'Infidel' has been used by Christians and Muslims to name the people outside their religious group, the ones who do not have faith (fides in Latin)." Weckman, pp. 64–65.
^ "Infidel" in An Introductory Dictionary of Theology and Religious Studies, p. 630