Wordnet 3.0
NOUN (1)
1.
a hole (in a door or an oven etc) through which you can peep;
[syn: peephole, spyhole, eyehole]
WordNet (r) 3.0 (2006):
spyhole
n 1: a hole (in a door or an oven etc) through which you can
peep [syn: peephole, spyhole, eyehole]