“Also called denotative or referential theories. Theories which equate the meaning of a word with an object it stands for (like the ‘FIDO’-FIDO Theory), or else with the word’s relation to such an object.
Proper names form the primary class, but general words can stand for abstract objects (‘dog’ for doghood, ‘red’ for the color red, and so on). A word like ‘dog,’ however, can also be taken to stand for different dogs on different occassions, which raises one of the standard objections to the theory: that it is unclear what ‘standing for’ amounts to, and how many different jobs it is supposed to do. See also Use Theories of Meaning.”
B. Russell, An Inquiry into Meaning and Truth (1940), especially chapters 1-7.