n. An earthquake whose epicentre is beneath the sea
the GNU version of the Collaborative International Dictionary of English
n. A quaking of the sea.
The Century Dictionary and Cyclopedia
n. An earthquake which takes place beneath the ocean.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. an earthquake at the sea bed
Word Usage
"No one seemed to think for a moment of danger, or took heed of the bustle on deck, or of the quivering and shaking of everything in the saloon, which seemed suffering from what Mr Lathrope styled a "seaquake" -- in contradistinction to earthquake."