nicotine: an alkaloid poison that occurs in tobacco; used in medicine and as an insecticide
vasoconstrictor: any agent that causes a narrowing of an opening of a blood vessel: cold or stress or nicotine or epinephrine or norepinephrine or angiotensin or vasopressin or certain drugs; maintains or increases blood pressure
acromphalus: abnormal protrusion of the navel; sometimes the start of umbilical hernia