[1] : The Collaborative International Dictionary of English v.0.48

trap \trap\, n. sw. trapp; akin to trappa stairs, dan. trappe,
   g. treppe, d. trap; -- so called because the rocks of this
   class often occur in large, tabular masses, rising above one
   another, like steps. see tramp. geol.
   an old term rather loosely used to designate various
   dark-colored, heavy igneous rocks, including especially the
   feldspathic-augitic rocks, basalt, dolerite, amygdaloid,
   etc., but including also some kinds of diorite. called also
   trap rock.
   1913 webster

   trap tufa, trap tuff, a kind of fragmental rock made up
      of fragments and earthy materials from trap rocks.
      1913 webster
see also:
tramp trap rock trap tufa trap tuff 

Booby Trap >> B Words
Booby Trap, definition of term: Booby Trap
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