stillson wrench

from WordNet (r) 3.0 (2006)
Stillson wrench
    n 1: a large pipe wrench with L-shaped adjustable jaws that
         tighten as pressure on the handle is increased
    
from The Collaborative International Dictionary of English v.0.48
Stillson wrench \Still"son wrench\
   A pipe wrench having an adjustable L-shaped jaw piece sliding
   in a sleeve that is pivoted to, and loosely embraces, the
   handle. Pressure on the handle increases the grip.
   [Webster 1913 Suppl.]
    

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