'Congenital' is Latin for 'born together with' — a condition present from birth.
Present from birth, especially of a disease or physical abnormality; having a particular trait as if from birth.
From Latin 'congenitus' (born together with, innate), the past participle of 'congignere' (to engender together, to produce jointly), composed of 'con-' (together, with) + 'gignere' (to beget, to produce, to bring into being). 'Gignere' is a reduplicated form from PIE *ǵenh₁- (to give birth, to beget, to produce), one of the most productive roots in Indo-European, yielding Latin 'genus' (birth, race, kind), 'gens' (clan), 'genius' (spirit of generation), 'ingenium' (inborn nature), and 'natura' (from 'nasci,' to be born). The same root *ǵenh₁-
The informal phrase 'congenital liar' uses a medical term metaphorically — it implies someone has been lying since birth, as though dishonesty were a birth defect. This figurative extension appeared in the nineteenth century and has become so common that many English speakers encounter 'congenital' more often in this colloquial sense than in its original medical one.