nom · noun, verb1
Short form of various words.
nom · interjection, verb2
Onomatopoeic, variant of num, num-num. Attested 2004 as om nom, om nom nom, popularized from 2007 in internet use, second place in the American Dialect Society’s "Word of the Year" 2010. From the catchphrase of Cookie Monster on Sesame Street, as at the end of “C Is For Cookie” (1971), made when devouring cookies. However, as late as 2009, this was canonically written with a ‘u’, as in S is for School! (2006), as “num num”, or in the press kit for the 40th season (2009), as “un num num num num”; by 2013 this was changed to the now-popular nom.
Etymology from Wiktionary, CC BY-SA 4.0.