How to say "sun" in Japanese

• 太陽たいようJLPT N3approx.Common
  nounThe sun as a celestial body — the star itself, as treated in astronomy or science. The common word when you mean the sun as an object rather than its light.
  マリーゴールドは太陽たいようとともに起おきる。↗

  The marigold rises with the sun.
• 寸すんCommon
  nounThis is not the star: it is a Japanese unit of length, about 3 cm, whose romanization happens to be 'sun'. For the celestial sense it is essentially never the word you want.
  寸すんを与あたえれば尺さしを望のぞむ。↗

  Give him an inch and he will take a yard.
• 日ひJLPT N4approx.Common
  nounCovers the sun in the sky and also sunshine and sunlight. The common word in ordinary talk about sunny weather or strong light, where 太陽 would suggest the astronomical object.
  この部屋へやはあまり日ひが当あたらない。↗

  This room does not get much sun.

Use 太陽 for the sun as a celestial body, 日 for the sun in the sky and for sunshine or sunlight, and 寸 not for the star at all: it is a unit of length of about 3 cm.

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

• 太陽たいようSun
• 寸すんsun (approx. 3 cm)
• サンSun
• 陽ひsun
• 日輪にちりんSun
• ソレイユsun
• 飛輪ひりんSun
• 山沢損さんたくそんsun (hexagram 41 of the I Ching: decrease)
• ののさまGod
• 日ひsun