宙|ちゅうchuu[1]atamadaka (head-high)

1. nounspace; air; midair
   暖あたたかい日ひには手足てあしを伸のばしたり、仰向あおむけになって足あしを宙ちゅうに上あげたまま寝ねることもある。↗

   On warm days, bears stretch out or lie on their backs with their feet in the air.
2. noun(from) memory; (by) heart

• Synonym空中くうちゅうNeutralObjective word for the space above the ground. 「宙」 suggests something hanging in midair or left undecided, as in 「宙に浮く」, and also covers reciting from memory.
• Related天てんWrittenWritten-style single character for the sky or heaven. 「宙」 describes a state of hanging in midair rather than the sky itself.
• Related大空おおぞらWrittenWritten word for the vast open sky, with a lyrical feel. 「宙」 is about a suspended state, not the sky itself.
• Related天空てんくうWrittenWritten word for the broad expanse of sky. 「宙」 instead evokes hanging in midair.
• Related天上てんじょうWrittenWritten word for the heavens, the deva realm, or ascending to heaven. 「宙」 stays at midair level.
• Related雲居くもいWrittenArchaic written word for the high skies or the imperial court. 「宙」 is about hanging in midair.
• Related一天いってんWrittenWritten word for the whole sky or the entire realm under heaven. 「宙」 suggests hanging in midair or being undecided.
• Related九天きゅうてんWrittenWritten word for the ninefold heavens or the imperial palace. 「宙」 describes a state of hanging in midair.
• Related上天じょうてんWrittenWritten word for the heavens above or the Creator, with a religious tinge. 「宙」 is about hanging in midair.
• Related天の原あまのはらWrittenArchaic written word for the vast firmament, redolent of classical poetry. 「宙」 describes hanging in midair.
• Related天球てんきゅうFormalFormal astronomical term for the celestial sphere imagined around the earth. 「宙」 instead suggests hanging in midair.
• Related太虚たいきょWrittenWritten word for the vast heavens, also an ancient Chinese philosophical concept. 「宙」 is about hanging in midair.
• Antonym地ちNeutralNeutral word for the ground or the earth; it is the opposite of 「宙」, which hangs in midair.
• Antonym土つちNeutralNeutral word for soil or the ground; it stands opposite 「宙」 hanging in the air.

「宙」 on its own lives mostly in set phrases: 「宙に浮く」 and 「宙ぶらりん」 for something hanging in midair or left undecided, and 「宙で言う」 for reciting from memory. For the objective space above the ground choose 「空中」; for the sky itself choose 「大空」 or 「天空」. The opposite of 「宙」 is 「地」, the ground.

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

1. 空中くうちゅうや空間くうかんのこと。
2. 暗記あんきしていて、何なんも見みないで言いえること。