From http://www.bristolinc.com/resource/electrical-glossary :
(a) A manual bending device used to bend rigid metal conduit (pipe hickey, conduit hickey).
(b) A coupling used to connect a luminaire to its supporting device (luminaire hickey, fixture hickey).
(c) The resultant burn when an arm or other body part comes into contact with the surface of a hot luminaire, usually during focus. (Long sleeves, people! And gloves.)
See the thread https://www.controlbooth.com/threads/term-luminaire-hickey.37451/ .
(a) A manual bending device used to bend rigid metal conduit (pipe hickey, conduit hickey).
(b) A coupling used to connect a luminaire to its supporting device (luminaire hickey, fixture hickey).
(c) The resultant burn when an arm or other body part comes into contact with the surface of a hot luminaire, usually during focus. (Long sleeves, people! And gloves.)
See the thread https://www.controlbooth.com/threads/term-luminaire-hickey.37451/ .