be a figment of (one's/the) imagination

To be an imagined experience (especially after one has initially thought it to be real). I thought I heard the sound of my front door opening last night but it turned out to be a figment of my imagination.

Common Names:

Name	Pronounced	Usage
Lionel	['laiənl]
Helewidis	-	Ancient Germanic
Bogdan	BAWG-dahn (Polish), BOG-dahn (Serbian, Croatian), bog-DAHN (Romanian)	Polish, Russian, Slovene, Bulgarian, Serbian, Croatian, Macedonian, Romanian, Medieval Slavic
Nkechi	-	Western African, Igbo
Heida	HIE-dah	German
Aniket	-	Indian, Hindi, Marathi