mployed in a statute which had at the time a well-known meaning ... in the law of this country, they are presumed to have been used in that sense," Standard Oil Co. v, United States, 221 U.S. 1, 59 (1911), § 2255's reference to "legal EFTA00207697 Case 9:08-cv-80893-KAM Document 128 Entered on FLSD Docket 03'05'