To answer the original question - I've also only ever kown this as the Chord.

Elaborating on the details - I play in a Scottish band, Accordion, Fiddle, Bass and Drums. We always start with a short upbeat from the accordion (In fact it's two notes, the dominant preceded by a short grace note a semitone lower. So in G it's C#,D) followed by a chord which is three beats long and then the upbeat for the dance on the fourth beat. The chord has two pulses, on the first and third beats and I play two bass notes one on the first beat and a second shorter note on the third beat. There are some dances where leading couples are required to change sides at the beginning of the dance which call for two starting chords.

The finishing chord is similar except there is no upbeat. The final bar of the dance is also "played out". That is to say there is a pulse, and bass note on the 3rd beat of the bar. (in 4/4) unlike English dances which more often finish on the first beat of the final bar.

Mitch