Pronunciation: (un-but'n), [key]
1. to free (buttons) from buttonholes; unfasten or undo.
2. to unfasten by or as if by unbuttoning: to unbutton a jacket.
3. to disclose (one's feelings, thoughts, etc.) after deliberate or prolonged silence.
to unfasten a button or one's buttons.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.