The Collaborative International Dictionary of English v.0.48:

holdover \holdover\ n.
   Any person or thing remaining from a previous period of use,
   tenure, etc; Specifically: an official who remains in office
   after his term.

   Syn: hangover.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

holdover
    n 1: an official who remains in office after his term [syn:
         holdover, hangover]
    2: something that has survived from the past; "a holdover from
       the sixties"; "hangovers from the 19th century" [syn:
       hangover, holdover]

Moby Thesaurus II by Grady Ward, 1.0:

56 Moby Thesaurus words for "holdover":
   afterglow, afterimage, balance, butt, butt end, candle ends, chaff,
   debris, detritus, end, fag end, filings, fossil, husks, incumbent,
   ins, jack-in-office, lame duck, leavings, leftovers, new broom,
   odds and ends, office-bearer, officeholder, offscourings, orts,
   parings, president-elect, public official, public servant, rags,
   refuse, relics, remainder, remains, remnant, residue, residuum,
   rest, roach, rubbish, ruins, rump, sawdust, scourings, scraps,
   shadow, shavings, straw, stubble, stump, survival, sweepings,
   trace, vestige, waste