The Collaborative International Dictionary of English v.0.48:

Stop-gap \Stop"-gap`\, n.
   That which closes or fills up an opening or gap; hence, a
   temporary expedient.
   [1913 Webster]

         Moral prejudices are the stop-gaps of virtue. --Hare.
   [1913 Webster]

WordNet (r) 3.0 (2006):

stopgap
    n 1: something contrived to meet an urgent need or emergency
         [syn: makeshift, stopgap, make-do]