Denoting non-existent objects

If I point to an object and say ‘table’, I can be said to be denoting the table. Now, how is it possible to denote objects that do not exist? It might be said that unicorns do not exist. This could be construed as inconsistent, since it effectively says that there are unicorns, but they do not exist, which is a contradiction. On this view, we cannot say that unicorns do not exist, since, to refer to a unicorn is for it to exist. It might be argued that to use the word ‘unicorn’ is to refer to the concept unicorn rather than to a unicorn itself. So, the concept unicorn exists when I say that unicorns do not exist, but this is not to say that unicorns themselves exist. Unicorns neither exist nor do they subsist. In which case, the meaning of the word ‘unicorn’ does not lie in denoting the object, but in denoting a description, e.g. a horse with a horn.