The Collaborative International Dictionary of English v.0.48:

Kauri resin \Kauri resin\, Kauri gum \Kauri gum\, or Kauri copal
\Kauri copal\
   A resinous product of the kauri, found in the form of yellow
   or brown lumps in the ground where the trees have grown. It
   is used for making varnish, and as a substitute for amber.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

kauri gum
    n 1: resin of the kauri trees of New Zealand; found usually as a
         fossil; also collected for making varnishes and linoleum
         [syn: kauri, kauri copal, kauri resin, kauri gum]