A very bad or frightening dream.
Any bad, miserable, difficult or terrifying situation or experience that arouses anxiety, terror, agony or great displeasure.
A feeling of extreme anxiety or suffocation experienced during sleep; Sleep paralysis.
To have a nightmare.
A state of dreaming while awake; a loose or irregular train of thought; musing or meditation; daydream.
An extravagant conceit of the imagination; a vision.