A love-bite or hickey/hickie is a temporary mark or bruise on one's skin (medically, a minor hematoma) resulting from kissing or sucking or biting forcefully enough to burst blood vessels beneath the skin.
Love bites last, depending on the person, from 4-12 days. Violinists and violists can easily receive a similar-looking mark on their neck from the pressure of the chin rest while practicing and are often mistaken for having a love bite.
There are many common cures for a hickey, one of the more common being a frozen spoon held to the site of infliction. A few other ways might include rubbing gently (sometimes with a warm towel), or rubbing vitamin K.
'Hickey' along with 'love-bite' are the most popular names for this type of bruise.