From WordNet (r) 2.0 (August 2003) [wn]:
Decker
n 1: English dramatist and pamphleteer (1572-1632) [syn:
Dekker, Decker, Thomas Dekker, Thomas Decker]
2: (often used in combinations) something constructed with
multiple levels; "they rode in a double-decker bus"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Decker \Deck"er\ (d[e^]k"[~e]r), n.
1. One who, or that which, decks or adorns; a coverer; as, a
table decker.
[1913 Webster]
2. A vessel or vehicle which has a deck or decks; -- used
esp. in composition; as, a single-decker; a three-decker;
a double-decker bus.
[1913 Webster +PJC]