This is the 489th most frequent Japanese word.
服
Clothes.
In this case, '服' is associated with the action of being suited to someone, reflecting style or appropriateness.
この服は私に似合うと思います。
I think these clothes suit me.
Here, '服' is discussed in a general sense as a category that includes specific types of garments.
ドレスも服の一種です。
A dress is also a type of clothing.
Here, '服' simply refers to clothing as an object that can be bought.