Green’s Dictionary of Slang

lerrycometwang n.

[the chorus of a contemporary popular song]

a fool, a simpleton.

[UK]J. Taylor ‘A Kicksey Winsey’ in Works (1869) II 36: A Kicksey Winsey: or A Lerry Come-Twang.
[UK]T. Duffet Mock-Tempest III ii: I never danc’d naked at the French house for Mild-Sixpences, goody Lerry-come-twang.