ACT: A written bill formally passed by a legislature, such as the U.S. Congress, and signed by an
executive, such as the U.S. president. An act is a bill from its introduction until its passage by a
legislature. An act becomes a law; becomes a formal statute, when it is signed by (or passed over
the veto of) a chief executive, such as the U.S. president. 2. A bill that has been passed by only one
house of a legislature.