bekpi experimental gismu

x1 is the 'back', dorsum of body x2

Opposite of ventral part of the body. Not necessarily should be a posterior part of the body. Determined by bilateral symmetry of the body. See also vente, trixe, cutne.

In notes:

vente
x1 is the ventral part of body x2
verteba
x1 is a vertebra of body or body-part x2