The Collaborative International Dictionary of English v.0.48:

Manila hemp \Manila hemp\ n.
   1. A fibrous material obtained from the abaca plant (Musa
      textilis), a plant allied to the banana, growing in the
      Philippine and other East India islands; -- called also by
      the native name abaca. From it matting, canvas, ropes,
      and cables are made.

   Syn: Manilla hemp, abaca.
        [1913 Webster]

   2. A Philippine plant (Musa textilis) having leafstalks
      that yield Manila hemp used for rope and paper etc.;
      called also the abaca.
      [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Abaca \Ab"a*ca\ ([a^]b"[.a]*k[.a]), n. [The native name.]
   The Manila-hemp plant (Musa textilis); also, its fiber. See
   Manila hemp under Manila.
   [1913 Webster]

WordNet (r) 3.0 (2006):

abaca
    n 1: a kind of hemp obtained from the abaca plant in the
         Philippines [syn: Manila hemp, Manilla hemp, abaca]
    2: Philippine banana tree having leafstalks that yield Manila
       hemp used for rope and paper etc [syn: abaca, Manila
       hemp, Musa textilis]