對著現在風向的（形容詞）
這是核心畫面直接的用法：東西、地方或人正對著現在的風向。
adjective · B1
Following the newest fashions, styles or ideas. You can use it about a thing, a place or a person, and it is an informal word.
時髦的／趕流行的
核心畫面
Fashion moves like wind: it blows one way this season and another way next. Trendy means turned the way the wind is blowing right now. The word is about the direction, not the quality — which is why the same word can sound like praise from one speaker and a small dig from another, and why it always carries a hint that this will pass.
可以想成流行像風：這一季往這邊吹，下一季往那邊吹。trendy 就是「現在正對著風向」。它講的是方向，不是好壞。所以…更多收起
可以想成流行像風：這一季往這邊吹，下一季往那邊吹。trendy 就是「現在正對著風向」。它講的是方向，不是好壞。所以同一個字從不同人嘴裡出來，有時候是稱讚，有時候是輕輕刺一下。也因為風會轉，這個字裡面本來就藏著「這陣子過了就不是了」的意思。From the word’s history
From trend + -y. Trend is the direction something is moving in, and -y means having that quality — so the word literally says "of the current direction".
字面上是 trend（潮流、風向）加 -y（帶有那個性質的），所以直譯就是「有風向味的」。這也解釋了為什麼它形容的從來不是東西本身好不好，而是它有沒有對著現在的風。
Wiktionary entry for trendy (kaikki:3f6f69a190036ae4:1084388072): "From trend + -y."
Two branches
一直轉身去對風向的人（名詞）
同一個畫面換成人：不是東西對著風向，而是一個人一直轉身去對風向，所以旁人看的是那個「一直轉」的動作。
noun · C1
A person who works hard at following every new fashion. A speaker who chooses this word is showing that they do not think much of that person.
趕時髦的人