Wordnet 3.0
NOUN (1)
1.
a surveyor's level having a short telescope fixed to a horizontally rotating table and a spirit level;
The Collaborative International Dictionary of English v.0.48:
Dumpy level \Dump"y lev"el\ (Surv.)
A level having a short telescope (hence its name) rigidly
fixed to a table capable only of rotatory movement in a
horizontal plane. The telescope is usually an inverting one.
It is sometimes called the Troughton level, from the name
of the inventor, and a variety improved by one Gavatt is
known as the Gavatt level.
[Webster 1913 Suppl.]
WordNet (r) 3.0 (2006):
Dumpy level
n 1: a surveyor's level having a short telescope fixed to a
horizontally rotating table and a spirit level