Two-lipped, as when the parts of a calyx or corolla form two clearly separated projections, usually an upper and a lower, as in Labiatae/Lamiaceae; in Compositae/Asteraceae, a corolla usually with two smaller adaxial lobes and an abaxial lamina with 3 lobes at the apex.
2-lipped, A bilabiate corolla has petals in two sets, commonly with two in upper and three in the lower.
Two-lipped, used when the calyx or corolla forms two separate projections as in many Lamiaceae.