1. a child afflicted by some disease or deformity whose picture is used on posters to raise money for charitable purposes; - Example: "she was the poster child for muscular dystrophy"
WordNet (r) 3.0 (2006):
poster child
n 1: a child afflicted by some disease or deformity whose
picture is used on posters to raise money for charitable
purposes; "she was the poster child for muscular dystrophy"