The Collaborative International Dictionary of English v.0.48:

Raft \Raft\, n. [Originally, a rafter, spar, and fr. Icel. raptr
   a rafter; akin to Dan. raft, Prov. G. raff a rafter, spar;
   cf. OHG. r[=a]fo, r[=a]vo, a beam, rafter, Icel. r[=a]f roof.
   Cf. Rafter, n.]
   1. A collection of logs, boards, pieces of timber, or the
      like, fastened together, either for their own collective
      conveyance on the water, or to serve as a support in
      conveying other things; a float.
      [1913 Webster]

   2. A collection of logs, fallen trees, etc. (such as is
      formed in some Western rivers of the United States), which
      obstructs navigation. [U.S.]
      [1913 Webster]

   3. [Perhaps akin to raff a heap.] A large collection of
      people or things taken indiscriminately. [Slang, U. S.] "A
      whole raft of folks." --W. D. Howells.
      [1913 Webster]

   Raft bridge.
      (a) A bridge whose points of support are rafts.
      (b) A bridge that consists of floating timbers fastened
          together.

   Raft duck. [The name alludes to its swimming in dense
      flocks.] (Zool.)
      (a) The bluebill, or greater scaup duck; -- called also
          flock duck. See Scaup.
      (b) The redhead.

   Raft port (Naut.), a large, square port in a vessel's side
      for loading or unloading timber or other bulky articles; a
      timber or lumber port.
      [1913 Webster]