Definition of poster child in English:

poster child

noun

North american
  • A person or thing that epitomizes or represents a specified quality, cause, etc.

    ‘the antiglobalization movement's poster child’
    ‘she's the poster child for cosmetic surgery’
    ‘the poster child of gluten-free grains, quinoa is a wonderful light, fluffy grain’
    • ‘He's the poster child for workers' rights, one of the key goals for the Freedom Ride.’
    • ‘Were there an Over-Clickers Anonymous, I could be their poster child.’
    • ‘This show is a poster child for why we love bad television; it makes us giddy inside, that's why.’
    • ‘I guess you could say she's the poster child for your pet project.’
    • ‘You became the poster child for every me-first, self-absorbed professional athlete on the planet.’
    • ‘I develop a soft spot for the domestic diva because I believe that she's being made out as a poster child for corporate misbehavior.’
    • ‘The wingers would love to use her as an example of an anti-appeasement poster child.’
    • ‘She would have been an appropriate poster child for the far left.’
    • ‘Morally, this guy is a poster child for the death penalty if he is tried and convicted of these crimes.’
    • ‘It seemed then, as it does now, that as soon as a company is held up as the poster child for how to create a successful business, it falls on hard times.’
    • ‘In 1984, she was implanted at no cost in Midland, Texas, as a poster child for a manufacturer's video.’
    • ‘But if you believe in capital punishment, as I do, it is very hard to find a better poster child than this sniper.’

Origin

1930s: from the use in print advertisements of good-looking young people and appealing children.