first wearing of new clothes
Refers to the occasion or act of wearing a new garment for the first time, often with a sense of ceremony or freshness.
I look forward to wearing new clothes for the first time at New Year's.
今日はスーツの着初めだ。
Today is the first wearing of the new suit.
A compound of 着 “wearing” and 初め “first occurrence,” with 初め voiced to ぞめ, denoting the first wearing of new clothes.