noun
citrus fruit segment; section of a citrus fruit
Refers to the individual juicy segments inside citrus fruits like oranges, grapefruits, and lemons. The word is usually written in kana.
みかんのじょうのうを一つずつ食べる。
I eat the mandarin orange segments one by one.
グレープフルーツのじょうのうを取り出すのが苦手だ。
I'm not good at removing grapefruit segments.
房 is a more general word for a bunch, cluster, or segment (e.g., a segment of an orange, a bunch of grapes, or a lock of hair). じょうのう is specifically the juicy segment of a citrus fruit.
果肉 means fruit flesh or pulp in general, not necessarily separated into segments. じょうのう refers to the natural segment structure of citrus fruits.
The word is composed of じょう (瓤, meaning pulp or segment) and のう (嚢, meaning sac or cyst). The exact historical derivation is uncertain, but the kanji reflect the meaning of a sac-like segment of pulp.