A noun can be used in a sentence as the subject of the sentence or of a clause within the sentence, as the object or indirect object of a transitive verb or its present participle used as a gerund in...
He has a total indifference to public opinion.
The clairvoyant was wearing a purple turban. If I were a clairvoyant I would tell you your future.If I could I would visit a clairvoyant.
I have finished the race.
The lab assistant placed a drop of blood on the slide.