夏|なつnatsu[2]odaka (tail-high)

1. noun, adverbsummer
   この夏なつ最高さいこうの暑あつさだ。↗

   It is the hottest this summer.

• Synonym夏場なつばNeutralRefers to the summer period, often paired with practical matters like business or weather, as in 「夏場はよく売れる」.
• SynonymサマーNeutralA loanword used mostly as the first element of compounds like 「サマーセール」 and 「サマーキャンプ」; it rarely stands alone for summer.
• Synonym夏季かきWrittenThe formal name for summer, used in writing and official contexts, as in 「夏季休暇」 and 「夏季オリンピック」; same meaning as 「夏」 but more formal.
• Synonym夏期かきWrittenTreats summer as a set period or term, as in 「夏期講習」 and 「夏期休業」; common in school and institutional schedules.
• Synonym夏時かじWrittenA written Sino-Japanese word for the summer season, used very rarely; say 「夏」 or 「夏季」 in everyday contexts.
• Related九夏きゅうかWrittenA Sino-Japanese literary name for the roughly ninety days of summer, found only in poetry and almost never used in modern Japanese.
• Related朱夏WrittenLiterary Sino-Japanese name for summer, from the old pairing of the color vermilion with summer; seen only in poetry and haiku — everyday speech says 「夏」.
• Related朱炎WrittenAn elegant written word evoking summer heat like fire; appears only in poetry or set phrases in letters. In daily speech say 「夏」 or 「暑さ」.
• Related炎節WrittenA written, elegant term for the hot summer, seen mostly in seasonal greetings at the start of letters; not used in everyday speech.
• Antonym冬ふゆNeutralThe season opposite 「夏」: the coldest of the four seasons.

Say 「夏」 for summer in everyday speech. Use 「夏季」 as the formal name, 「夏期」 for school or business terms, and 「サマー」 in loan compounds. The remaining Sino-Japanese names — 「朱夏」, 「朱炎」, 「夏時」, 「炎節」, 「九夏」 — appear only in poetry and letters.

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

1. なつ 季節きせつ（四季しき）の一ひとつ。春はるの次つぎ、秋あきの前まえ。