- 1
With no sunshine — used for a place or a stretch of time where the sun does not reach or does not come out: a sunless room at the back of a building, a sunless week of rain, a sunless winter afternoon. It is a slightly literary word, more common in writing than in speech; in conversation people say "there's no sun" or "it's grey". It usually carries a mood with it — cold, dull, a bit depressing — so writers reach for it when they want that feeling. One modern exception runs the other way: "sunless tanning" is the advertising term for creams and sprays that brown your skin without sun, and there the word is neutral and technical.
沒有陽光的、照不到太陽的（文學色彩，帶點陰暗沉悶的感覺）
組成sun + -less, the ending meaning "without". The -less ending goes back to Old English -lēas, from a root meaning loose or free of something — the same idea as "free of", not the "less" that means smaller amount.
原始詞典資料2 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
sunlessadj
- 1
Without the sun or sunshine; shaded; shadowed.
- In Xanadu did Kubla Khan / A stately pleasure-dome decree: / Where Alph, the sacred river, ran / Through caverns measureless to man / Down to a sunless sea.
- 2
Dreary, cheerless.
- When I first saw her, her countenance was sunless, her complexion colourless; she looked like one who had no source of enjoyment, no store of bliss anywhere in the world.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。