abaxial
ab·ax·i·al
Of a side that is facing away from the axis or central line, such as the underside of…Of a side that is facing away from the axis or central line, such as the underside of a leaf, or the back of an animal.
US/ˌæˈbæk.si.əl/
Meaning
2 senses(not comparable)Of a side that is facing away from the axis or central line, such as the underside of a leaf, or the back of an animal.
facing away from the axis of an organ or organism
(not comparable)Not in the axis. Applied to an embryo placed out of the axis of the seed.