noun, noun or participle which takes 'suru'
first election victory; being elected for the first time
Used in political contexts when a candidate wins an election for the first time. Can function as a noun or take する to describe the act of winning one's first election.
彼は昨年の選挙で初当選を果たした。
He achieved his first election victory in last year's election.
新人候補が初
The new candidate was elected for the first time.