I don't understand "chord around the circle". In my limited
recollection, a chord can only exist inside a circle. a.k.a. a
straight line segment with end points on the circumference.

Could it be the length of one of the (two possible) sections of the
'circumference' which is defined by the chord endpoints?

Unless you're talking music, guitar chords and the circle of fifths.
(which, though I should, I don't know anything about anyway)