Caviar tongue (also termed sublingual varicosities or sublingual varices), is a condition characterized by purplish venous ectasias commonly found on the ventral (undersurface) of the tongue after the age of fifty. It is normal for there to be veins visible underneath the tongue, partly because the mucous membrane is so thin and translucent in this region, but where these vessels become dilated and tortuous, they may appear round and black like caviar.