Allusion – A reference intended to call something to mind without directly mentioning it
A strange illusion (allusion). I suppose it was a reference to a rabbit in a hat but that wasn't mentioned directly when the magician pulled a mouse from a shoe.
Examples of allusion in a sentence:
She made no allusion to the incident.
Harry was unsure if his friend was making some allusion to him.
She made and allusion about her ex-boyfriend in her song.