na-adjective, noun which may take the genitive case particle 'no', noun
deepest
Used as a noun or adjectival noun to describe the greatest depth, often in geographical, emotional, or abstract contexts.
この湖の最深部は約100メートルです。
The deepest part of this lake is about 100 meters.
彼の言葉は私の心の最深に響いた。
His words resonated in the deepest part of my heart.