Underbelly is the side of something that is not normally seen. Figuratively, it means a vulnerable or weak part, similar to the term Achilles' heel, or alternatively, a hidden, illicit side of society.
This term could refer to:
Business
Underbelly Limited, an entertainment company in the UK
Television Australia and New Zealand Underbelly (TV series), an Australian true crime drama television series, that borrows the title of the book series by journalists John Silvester and Andrew Rule and is primarily based on other works by the same authors: Underbelly (series 1), a 2008 Australian television drama mini-series and first in the franchise Underbelly: A Tale of Two Cities, a 2009 Australian drama mini-series prequel to the franchise Underbelly: The Golden Mile, a 2010 Australian drama mini-series prequel in succession to Tale Underbelly: Razor, a 2011 Australian drama mini-series, fourth in the franchise Underbelly: Badness, a 2012 Australian drama mini-series, fifth in the franchise Underbelly: Squizzy, a 2013 Australian drama mini-series, sixth in the franchise Underbelly: Vanishing Act, a 2022 Australian drama mini-series, seventh in the franchise Underbelly Files, an Australian drama mini-series trilogy that continues the original Underbelly series. It consists of four 2-hour length telemovies titled: Tell Them Lucifer Was Here, a 2011 Australian made-for-television movie Infiltration, a 2011 Australian made-for-television movie The Man Who Got Away, a 2011 Australian made-for-television movie Underbelly Files: Chopper a 2017 Australian mini-series Underbelly NZ: Land of the Long Green Cloud, a 2011 New Zealand spin-off of the Australian series Fat Tony & Co., a 2014 Australian true crime drama television series and the unbranded sequel to the first series Informer 3838, a 2020 Australian spin-off of the Underbelly series
United States Notes from the Underbelly, an American television sitcom
Music Underbelly (soundtrack) "The Underbelly", a song by Died Pretty in the 1990 album Every Brilliant Eye