奥深い|おくふかいokufukai[4]nakadaka (mid-high)

1. i-adjectiveprofound; deep
2. i-adjectivedeep (of a cave, etc.); innermost; interior
   その話はなしは、ある日曜日にちようびの午後ごごも遅おそくなった頃ころ、奥深おくふかい森もりの中なかで始はじまったんだ。↗

   It began late one Sunday afternoon, deep in the woods.

• Synonym深いふかいNeutralThe most versatile word for 'deep': water depth, deep ties, etc. 「奥深い」 instead stresses secluded depths and rich meaning.
• Synonym深遠しんえんWrittenWritten word for something profound and unfathomable, as in 「深遠な哲理」; stresses depth of thought rather than physical depth.
• Synonym深奥しんおうWrittenWritten word for the abstruse — hard to fathom — or for the depths of an art or the mind; stresses the mysteries of scholarship.
• Related深長しんちょうWrittenMostly in 「意味深長」 = loaded with meaning. Standing alone it is a written word; stresses speech that hints at more than it says.
• Related深甚しんじんWrittenFormal, courteous word for deep feeling or gratitude, mostly in set phrases like 「深甚なる謝意」; not for everyday speech.
• Related奥妙おうみょうWrittenWritten word for something subtle and unfathomable; rare, so in daily speech say 「奥深い」.
• Related甚深じんしんWrittenExtremely profound; mostly the Buddhist term 「甚深」. Written and not used in everyday speech.
• Antonym浅いあさいNeutralAntonym: shallow or superficial. Opposes 「奥深い」 both for physical depth and depth of thought.

Use 「奥深い」 for places hidden deep inside or things rich in meaning, as in 「奥深い山」 and 「茶道は奥深い」. For plain depth say 「深い」; for profound thought 「深遠」. The other Sino-Japanese words are written/formal; the antonym is 「浅い」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 入り口いりぐちなどから奥おくがある。
2. 意味いみが深ふかく分わかりづらい。