From Longman Dictionary of Contemporary Englishbirthmarkbirth‧mark /ˈbɜːθmɑːk $ ˈbɜːrθmɑːrk/ noun [countable] MIMARKa permanent mark on your skin that you have had since you were born Paul had a birthmark on his left cheek.
Examples from the Corpus
birthmark• The police identified the girl from a birthmark on her leg.• Did he have a birthmark there?• Scar tissue all right; a birthmark she'd had removed in early teens in case it turned malignant.• You like a beer, sweet thing with a birthmark?• Please help little Jenny At last there's hope for the many hundreds of children whose lives are made a misery by birthmarks.• Now the vital laser needed to treat children with disfiguring birthmarks is already installed at the Ulster Hospital at Dundonald.• He had a star-shaped birthmark, and so was pronounced lucky.• The subject of International Relations grew out of this intellectual and political setting; and it bore the birthmarks of its origins.• Patients were told they would just have to live with the birthmarks. 