What does arcuation mean?
The definition of arcuation
Arc`u*a”tion, n.
Etym: [L. arcuatio.]

1 The act of bending or curving; incurvation; the state of being bent; crookedness. Coxe.
2 (Hort.)
A mode of propagating trees by bending branches to the ground, and covering the small shoots with earth; layering. Chambers.