Wordnet 3.0
NOUN (1)
1.
a large pipe wrench with L-shaped adjustable jaws that tighten as pressure on the handle is increased;
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.]
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