To perform an act; behave; do; perform on the stage.
A law.
The exertion of power; something done; a deed.
A section of a play or drama.
Act in a play. – Signora Fantastici by Madame de Stael, translated by Frank J. Morlock
But how to act? – The Crisis, Complete by Winston Churchill Last Updated: March 6, 2009
My dear, they do not act like married people. – The Window-Gazer by Isabel Ecclestone Mackay