The Collaborative International Dictionary of English v.0.48:

Laudanum \Lau"da*num\, n. [Orig. the same wort as ladanum,
   ladbdanum: cf. F. laudanum, It. laudano, ladano. See
   Ladanum.]
   Tincture of opium, used for various medical purposes.
   [1913 Webster]

   Note: A fluid ounce of American laudanum should contain the
         soluble matter of one tenth of an ounce avoirdupois of
         powdered opium with equal parts of alcohol and water.
         English laudanum should have ten grains less of opium
         in the fluid ounce. --U. S. Disp.
         [1913 Webster]

   Dutchman's laudanum (Bot.) See under Dutchman.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dutchman \Dutch"man\, n.; pl. Dutchmen.
   A native, or one of the people, of Holland.
   [1913 Webster]

   Dutchman's laudanum (Bot.), a West Indian passion flower
      (Passiflora Murucuja); also, its fruit.

   Dutchman's pipe (Bot.), .
      [1913 Webster] Dutchman's breeches