Definition of jack-boy in English:

jack-boy

noun

rare
  • A boy employed to do menial or servile work; specifically a stable boy, a groom, a postilion.

Origin

Mid 16th century; earliest use found in Thomas Tusser (c1524–1580), writer on agriculture and poet. From Jack + boy.

Pronunciation

jack-boy

/ˈdʒakbɔɪ/