anything done, being done, or to be done; deed; performance: a heroic act.
the process of doing: caught in the act.
a formal decision, law, or the like, by a legislature, ruler, court, or other authority; decree or edict; statute; judgment, resolve, or award: an act of Congress.
an instrument or document stating something done or transacted.
one of the main divisions of a play or opera: the second act of Hamlet.