Final answer:
The missing word in the song 'Lydia the BLANK Lady' by Groucho Marx is 'Tattooed'. The song is from the 1939 film 'At the Circus' and is a well-known number by Groucho Marx.
Step-by-step explanation:
The line 'She has eyes that folks adore so / And a torso even more so' comes from the Groucho Marx song titled 'Lydia the Tattooed Lady.' This song is from the 1939 movie 'At the Circus' and has become one of the signature songs associated with Groucho Marx during his career.
The blank in the line from the Groucho Marx song "Lydia the BLANK Lady" should be filled with the word "dancing". This line describes Lydia as having a beautiful torso and eyes that people adore. The use of the word "dancing" suggests that Lydia's whole presence exudes joy, playfulness, and grace.