Wordnet 3.0
NOUN (1)
1.
a geologist skilled in hydrology;
The Collaborative International Dictionary of English v.0.48:
Hydrologist \Hy*drol"o*gist\, n.
One skilled in hydrology.
[1913 Webster]
WordNet (r) 3.0 (2006):
hydrologist
n 1: a geologist skilled in hydrology