the devil; Satan.
Words That Are Older Than You ThinkThe first citation of "OMG" in the Oxford English Dictionary appears in a 1917 letter from the British admiral John Arbuthnot Fisher to Winston Churchill.
Origin of Old Nick
First recorded in 1660–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for old nick
informal a jocular name for Satan
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012