noun

• (originally Britain, aviation, Royal Air Force slang)
• (obsolete) A contemptible person.
• An imaginary creature reputed to be mischievously inclined, for example, to damage or dismantle machinery.
• (by extension)
• Any mysterious, unknown source of mischief or trouble, or the problem created thereby.
• (surfing, skateboarding, slang) A young, inexperienced surfer or skateboarder, regarded as a nuisance.