Green’s Dictionary of Slang

1. to dance.

1926

Van Vechten Nigger Heaven 281: ’Toly, you sho’ is one bardacious scroncher. You’s goin’ git scronched.

2. (also scrontch) in fig. use, to participate in any activity.

1974

(con. late 1940s) E. Thompson Tattoo (1977) 521: What was wrong with that? he wondered. I mean she was there when the scrontchin was done.