act on, acton

Act on or act on ( two words ) means to do something; to exert force or energy [ act ], with respect or regard for, or with the thought of [ on ]--
He felt a surging resentment, but he refused to act on it.
He was quick to make a resolution, but slow to act on it.
Act on or act on ( two words ) might also mean to take part in a show or play [ act ], atop or supported by [ on ]--
He liked to read the plays aloud, but he refused to act on the stage.

Acton or acton ( one word ) means a quilted or padded garment worn under mail or armor, in medieval times--
They removed his mail and his acton, to have a look at his wound.
The arrow penetrated his mail, but stuck in his acton; it only scratched his side.

Now that you know that, you can say--
"All was lost. He lay with his acton soaked in blood; his subordinates refused to act on his command."