from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. To perform (a role) weakly or with insufficient expressiveness.
- transitive v. To understate (a role) intentionally; underplay.
- intransitive v. To perform in an understated way.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To act in an understated manner or with little expressiveness
from the GNU version of the Collaborative International Dictionary of English
- transitive v. To perform inefficiently, as a play; to act feebly.
from The Century Dictionary and Cyclopedia
- To act or perform, as a play or part, inefficiently.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- v. act (a role) with great restraint
From under- + act. (Wiktionary)