One way to hold this word: hold a piece of brass. It is yellow, it throws light back at you, it is hard under your thumb, and if you knock it the note rings out and carries. Now notice that it is not gold — close, but harder and cheaper. Every use of brassy is one of those four things lent to something else: the yellow shine, the ringing note, the hardness that will not give way, and that small gap between looking like gold and being it.
From the word’s history
The adjective is simply brass plus -y, the ending that means 'having the quality of'. So the word has never pointed anywhere except back at the metal; everything it describes is being compared to brass.
這個形容詞就是 brass（黃銅）加上 -y。-y 的意思是「帶有某種性質的」。所以這個字從頭到尾都指著同一塊金屬。它形容什麼，就是在說那樣東西「有黃銅的味道」。顏色、聲音、態度，都是這一塊金屬借出去的。
Wiktionary entry supplied in this evidence packet (source_ref kaikki:3f6f69a190036ae4:613425170)
登入就可以看每一支怎麼連回核心畫面。