日光|にっこうnikkou[1]atamadaka (head-high)

1. nounsunlight; sunshine; sunbeams
   この部屋へやはあまり日光にっこうが当あたらない。↗

   This room gets little sunshine.
2. nounNikkō (city in Tochigi)
3. noun, BuddhismSuryaprabha (bodhisattva)

• Synonym日差しひざしNeutralSunlight shining down, often with a nuance of season or strength, as in 「強い日差し」; 「日光」 is the general term for sunlight, as in 「日光浴」 and 「直射日光」.
• Synonym陽光ようこうWrittenWritten word for bright, radiant sunshine with a literary feel; in everyday speech 「日差し」 is more common.
• Synonym天日てんぴNeutralThe sun's light and heat; mostly seen in 「天日干し」 (sun-drying). 「日光」 is the broader everyday word.
• SynonymサンシャインNeutralLoanword from English; mostly used in shop and product names. For everyday use, 「日光」 or 「日差し」 is natural.
• Synonym日の目ひのめNeutralMostly in the idiom 「日の目を見る」, meaning to finally see the light of day; rarely used for sunlight itself.
• Synonym太陽光線たいようこうせんWrittenWritten, scientific-sounding term for the sun's rays; in daily conversation 「日光」 is the natural choice.
• Synonym太陽光たいようこうNeutralCommon in energy and technology contexts, as in 「太陽光発電」 (solar power generation); 「日光」 is the more everyday word.
• Related日射にっしゃWrittenMeteorological term for solar radiation or insolation; in everyday speech 「日差し」 is what you'd say.
• RelatedデイライトNeutralRare loanword; today it mostly refers to a car's daytime running lights. Say 「日光」 for daylight in everyday Japanese.
• Related昼光ちゅうこうWrittenWritten term for natural daylight, used mainly in lighting and photography; everyday speech prefers 「日光」.
• Antonym月光げっこうNeutralAntonym in terms of light source: moonlight, as opposed to the sun's light.

For sunlight in general, say 「日光」, as in 「直射日光」. To describe sunlight shining down, use 「日差し」. 「太陽光」 fits energy and technology, 「天日」 sun-drying, and the antonym is 「月光」.

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

1. 太陽たいようの光ひかり。サンシャイン。
2. 栃木県とちぎけんにある地名ちめい。日光にっこう山やま及および日光にっこう東照宮とうしょうぐうにより著名ちょめい。