noun, noun which may take the genitive case particle 'no'
Refers to the bottom part or supporting structure of something, often in technical, architectural, or biological contexts. Can also be used attributively with の.
この建物の基部は鉄筋コンクリートでできている。
The base of this building is made of reinforced concrete.
葉の基部が少し黄色くなっている。
The base of the leaf is turning a little yellow.
Compound of 基 (ki, 'base, foundation') and 部 (bu, 'part, section'). The reading きぶ is the on'yomi for both characters.