noun
seltzer; carbonated water
Refers to plain carbonated water, often used as a mixer or refreshing drink. The term is a direct loan from English and is common in modern Japanese.
ウイスキーをセルツァーで割って飲む。
I drink whiskey mixed with seltzer.
冷たいセルツァーが飲みたい。
I want to drink some cold seltzer.