noun.
A huge mass of ocean-floating ice which has broken off a glacier or ice shelf
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
a large mass of ice floating at sea; usually broken off of a polar glacier
noun.
lettuce with crisp tightly packed light-green leaves in a firm head
Word Usage
" Most of the ice in an iceberg is underwater, leaving only the tip of the iceberg visiblea fact that is often alluded to in discussions of subjects in which the most important aspects are hidden from view."