/proh jear"ee euh/ , n. Pathol.
a rare congenital abnormality characterized by premature and rapid aging, the affected individual appearing in childhood as an aged person and having a shortened life span.
[ 1900-05; progér ( os ) prematurely old ( pro- PRO- 2 + gêr ( as ) old age + -os adj. suffix) + NL -ia -IA ]