From The Fiddler's Companion:

FAITHLESS NANCY DAWSON. AKA and see "A-Rovin." English, Country Dance Tune (4/4 time). D Major. Standard. One part. The title may refer to the Nancy Dawson who was a famous stage dancer in London in the 1760's. Barnes (English Country Dance Tunes), 1986. Laufman (Okay, Let's Try a Contra, Men on the Right, Ladies on the Left, Up and Down the Hall), 1973; pg. 27 (appears as "A-Roving").

On the "Nancy Dawson" song & tune, see The South Riding Tune Book.