501(c)(4) noun2 •(US) An organization that complies with section 501(c)(4) of the U.S. federal tax code. A non-profit organization exempt from some federal income taxes, due to being dedicated social welfare purposes. •(US) A nominally civic oriented service non-profit organization, that spends just over 50% of its revenues on such apparent aims, while spending the remainder on political purposes; due to the effect of the Citizens United judgment. forms501(c)(4)s
