降下|こうかkouka[0]heiban (flat)

1. noun, suru verb, intransitive verbdescent; fall; drop; (atmospheric) depression
   その大型おおがた機きは鋭するどい音おとを立たててほとんど直角ちょっかくに降下こうかした。↗

   The giant plane screamed down in an almost vertical dive.
2. noun, suru verb, intransitive verbpassing down (of an order, decree, etc.)

• Synonym下降かこうNeutralNeutral noun for a fall or decline, as in 「気温の下降」; the most versatile of the group, while 降下 leans formal.
• SynonymさがりNeutralNeutral noun for a lowering or drooping; it also means hand-me-downs or castoffs, as in 「お下がり」— senses 降下 lacks.
• Related下垂かすいWrittenA written-style noun for drooping or hanging down, as in 「胃下垂」; it stresses the sagging state itself, not movement downward like 降下.
• Antonym上昇じょうしょうNeutralNeutral noun for a rise, as in 「気温上昇」; the direct opposite of 降下 in its descent sense.
• Antonym上がるあがるNeutralNeutral, everyday verb for going up, as in 「熱が上がる」; common in speech, opposite of 降下.
• Antonym上昇するWrittenWritten-style verb for rising, as in 「株価が上昇する」; the formal counterpart opposing 降下.

Use 「降下」 for descending from a height or an order being handed down, as in 「パラシュート降下」「大命降下」. For everyday falls and declines pick 「下降」, for drooping 「下垂」, for rises 「上昇」 or 「上がる」.

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

1. 高たかい所ところから降おりること。
2. 高たかい地位ちいの人ひとから命令めいれいなどが下くだること。