The Collaborative International Dictionary of English v.0.48:

in-basket \in-basket\ n.
   a wood or metal receptacle placed on a desk to hold incoming
   material requiring attention, especially documents.

   Syn: in-tray, in-box.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

in-basket
    n 1: a wood or metal receptacle placed on your desk to hold your
         incoming material [syn: in-basket, in-tray] [ant: out-
         basket, out-tray]