From The Collaborative International Dictionary of English v.0.48 [gcide]:
1. The act of proscribing; a dooming to death or exile; outlawry; specifically, among the ancient Romans, the public offer of a reward for the head of a political enemy; as, under the triumvirate, many of the best Roman citizens fell by proscription.
From WordNet (r) 3.0 (2006) [wn]:
Definitions retrieved from the Open Source DICT dictionary. Click here for database copyright information.