When I was making my presentation at TUG 2019 he suggested _dart_ as a term for a shape of "two straight edges, one concave arc" which then freed up _arrowhead_ for "two convex, one concave arc".
You missed out on a great time at TUG26 [0], but hopefully I'll see you at TUG27 [1] in Paris :).
TUG28 will maybe be in Toronto (but this not official yet and could still easily change), which is pretty close to the US east coast.