Word Of The Day

Dorland's Word of the Day is a great way to broaden your knowledge of medical terminology. With a new and interesting term brought to you from the 32nd edition of Dorland's Illustrated Medical Dictionary each day, it's an easy and fun way to increase your medical vocabulary!

You can view a new word on this website each day.

Today's Word

actinic purpura

benign sun-induced damage to the dermis, usually on sun-exposed parts of the arms and hands of elderly persons, with darkened macules and patches; sometimes it may be from minor trauma or shearing movements. Called also solar purpura.

Word of the Day Archive

gene family

a group of genes with a similar DNA sequence and evolved from a common ancestral gene by duplication and variation; they may cluster on a single chromosome.

Pfiesteria

a genus of minute, plantlike protozoa of the phylum Dinoflagellata, the cause of red tide in coastal waters of the southeastern United States. The species P. piscicida produces a neurotoxin during one stage of its life cycle that can cause skin lesions and sometimes death in fish, as well as mild neurotoxicity in humans

inoculation hepatitis

any type of viral hepatitis spread by inoculations or injections, most commonly hepatitis B or hepatitis C.

weathering nodules

asymptomatic white papules on the helices of the ears, usually seen in elderly light-skinned men who have spent considerable time outdoors.

mitochondrial diseases

a diverse group of mainly multisystemic and maternally inherited disorders caused by mutations of mitochondrial DNA; some are sporadic and tissue-specific. They affect tissues having a high rate of oxidative metabolism, including the brain and peripheral nervous system, skeletal muscle, heart, liver, pancreas, kidneys, and endocrine system. Manifestations include encephalopathy, peripheral neuropathy, vision and hearing deficits, muscle pain and weakness, cardiac disease, renal tubular acidosis, liver failure, diabetes mellitus, short stature, and developmental delays.

ion channelopathy

any of numerous hereditary conditions caused by mutations in genes encoding ion channels, resulting in abnormal function of the channels. Those involving calcium channels in heart muscle can cause Brugada syndrome or long QT syndrome; those involving sodium or potassium channels of nerves can cause familial periodic paralysis. Called also ion channel disorders.

raccoon eyes

areas of ecchymosis around both eyes, most often indicating a basilar skull fracture; a similar finding is seen in primary amyloidosis. Called also raccoon sign.