The Collaborative International Dictionary of English v.0.48:

Sandarach \San"da*rach\, Sandarac \San"da*rac\,, n. [L.
   sandaraca, Gr. ?.]
   1. (Min.) Realgar; red sulphide of arsenic. [Archaic]
      [1913 Webster]

   2. (Bot. Chem.) A white or yellow resin obtained from a
      Barbary tree (Callitris quadrivalvis or Thuya
      articulata), and pulverized for pounce; -- probably so
      called from a resemblance to the mineral.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

citronwood \citronwood\ n.
   1. wood of a citron tree.
      [WordNet 1.5]

   2. a durable fragrant wood used in building (as in the roof
      of Cordova Cathedral); -- called also sandarac.

   Syn: sandarac.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

sandarac
    n 1: durable fragrant wood; used in building (as in the roof of
         the cathedral at Cordova, Spain) [syn: sandarac,
         citronwood]
    2: a brittle and faintly aromatic translucent resin used in
       varnishes [syn: sandarac, sandarach]
    3: large coniferous evergreen tree of North Africa and Spain
       having flattened branches and scalelike leaves yielding a
       hard fragrant wood; bark yields a resin used in varnishes
       [syn: sandarac, sandarac tree, Tetraclinis articulata,
       Callitris quadrivalvis]