Any bad, miserable, difficult or terrifying situation or experience that arouses anxiety, terror, agony or great displeasure.
A very bad or frightening dream.
A feeling of extreme anxiety or suffocation experienced during sleep; Sleep paralysis.
To have a nightmare.
A feeling of apprehension, doubt, fear etc.
A prick of the conscience; a moral scruple, a pang of guilt.
A sudden sickly feeling; queasiness.
To have a sickly feeling.