From The Collaborative International Dictionary of English v.0.48 :
Denotation \De`no*ta"tion\, n. [L. denotatio: cf. F.
d['e]notation.]
The marking off or separation of anything. --Hammond.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
denotation
n 1: the act of indicating or pointing out by name [syn:
indication, denotation]
2: the most direct or specific meaning of a word or expression;
the class of objects that an expression refers to; "the
extension of `satellite of Mars' is the set containing only
Demos and Phobos" [syn: reference, denotation,
extension]