Definition of nothingburger in US English:

nothingburger

noun

US
informal
  • Something that is or turns out to be insignificant or lacking in substance.

    ‘another nothingburger of a debate’
    as modifier ‘a seemingly endless series of nothingburger speeches’

Origin

1950s: from nothing and burger.

Pronunciation

nothingburger

/ˈnəθɪŋˌbərɡər//ˈnəTHiNGˌbərɡər/