noun
central part; middle section; center
Refers to the central area or middle portion of a physical space, object, or region. Often used in geographical, architectural, or organizational contexts.
この建物の中央部には大きなホールがあります。
There is a large hall in the central part of this building.
台風は明日、本州の中央部を通過
The typhoon is expected to pass through the central part of Honshu tomorrow.
真ん中 is a casual, everyday word for the exact middle point or center, whereas 中央部 is more formal and often used in descriptions of larger structures or regions.
Compound of 中央 (ちゅうおう, 'center') and 部 (ぶ, 'part' or 'section'). The reading is the standard on'yomi for each kanji.