Definition of Peck's bad boy in US English:

Peck's bad boy

noun

US
slang
  • An unruly or mischievous child.

Origin

Late 19th century; earliest use found in Peck's Sun. From Peck's bad boy, the name of a mischievous fictional character created by George Wilbur Peck for a serial in his newspaper Peck's Sun (Milwaukee, Wisconsin), which was first published in book form in 1883.

Pronunciation

Peck's bad boy

/ˌpɛks bad ˈbɔɪ/