To undo the buttons on clothing — a shirt, a coat, a blouse, a cuff, a pocket — so that it opens. Plain and physical, like unbuckle.

To undo the buttons on clothing解開衣物上的鈕扣 — a shirt, a coat, a blouse, a cuff, a pocket像襯衫、外套、女用上衣、袖口、口袋 — so that it opens讓它打開。Plain and physical樸實、動作性的意思，like unbuckle就像unbuckle（解開扣環）一樣。

You can unbutton the whole garment (he unbuttoned his shirt) or just part of it (she unbuttoned the top button, he unbuttoned his collar). Both are normal.

You can unbutton the whole garment你可以解開整件衣服的鈕扣 (he unbuttoned his shirt)（he unbuttoned his shirt）or just part of it或只解開一部分 (she unbuttoned the top button, he unbuttoned his collar)（she unbuttoned the top button, he unbuttoned his collar）。Both are normal兩種說法都很正常。

Notice that this verb is fussier than it looks: the fastener really has to be a button. A zip is unzipped, a buckle is unbuckled, a knot is untied. English names the mechanism.

Notice注意 that this verb is fussier than it looks這個動詞其實比看起來還挑剔：the fastener really has to be a button扣件真的必須是鈕扣才行。A zip是拉鍊 is unzipped要用unzip，a buckle是扣環 is unbuckled要用unbuckle，a knot是結 is untied要用untie。English names the mechanism英文是照著機關的種類來取動詞名稱的。

Two small extras worth knowing. The past participle works as an adjective and is very common in descriptions of people: he stood there with his collar unbuttoned.

Two small extras worth knowing有兩個小重點值得知道。The past participle過去分詞的形式 works as an adjective可以當形容詞用，and is very common in descriptions of people在描寫人的時候很常見：he stood there with his collar unbuttoned he stood there with his collar unbuttoned（他站在那裡，領子沒扣）。

And there is a figurative use for people — to unbutton, or to be unbuttoned, means to relax and stop being stiff and formal. Unbuttoned in that sense describes a loose, easy, unguarded mood: an unbuttoned interview, an unbuttoned laugh. It is not very frequent, and it belongs to writing more than to speech, but you will meet it, and it comes straight from the picture of a man loosening his collar after work.

And there is a figurative use for people還有一個用在人身上的比喻用法 — to unbutton, or to be unbuttoned也就是to unbutton或be unbuttoned，means to relax and stop being stiff and formal意思是放鬆下來，不再拘謹、不再一本正經。Unbuttoned in that sense在這個意義下的unbuttoned describes a loose, easy, unguarded mood形容一種鬆弛、自在、卸下防備的氣氛：an unbuttoned interview一場放鬆的訪談，an unbuttoned laugh一陣毫無拘束的笑聲。It is not very frequent這個用法不算太常見，and it belongs to writing more than to speech比較屬於寫作而不是口語，but you will meet it但你會遇到它，and it comes straight from the picture of a man loosening his collar after work而它就是直接來自一個男人下班後鬆開領子的那個畫面。