noun which may take the genitive case particle 'no'
ventral; abdominal side
Anatomical term referring to the front or belly side of an organism; often contrasted with 背側 (dorsal).
See also: 背側
胎児の腹側を超音波で確認した。
We confirmed the ventral side of the fetus with ultrasound.
この魚の腹側は白く、背側は青い。
The ventral side of this fish is white, and the dorsal side is blue.