Definition of sandboy in English:

sandboy

noun

in phrase as happy as a sandboy
  • Extremely happy or carefree.

    • ‘When he came back to Europe he married a Dutch girl and is now back in the Pacific as happy as a sand boy.’

Origin

Probably originally denoting a boy hawking sand for sale.

Pronunciation

sandboy

/ˈsan(d)bɔɪ/