content-based restriction. Constitutional law. A restraint on the substance of a particular type of speech. • This type of restriction are presumptively invalid but can survive a constitutional challenge if it is based on a compelling state interest and its measures are narrowly drawn to accomplish that end. Boos v. Barry, 485 U.S. 312, 108 S.Ct. 1157 (1988). See SPEECH (1). [Cases: Constitutional Law 90(3). C.J.S. Constitutional Law §§ 502, 542, 546–550.]