This is the 1194th most frequent Japanese word.
結婚
Marriage.
The word '結婚' is used as part of a verb phrase '結婚する', meaning 'to get married'. Here it is conjugated to the past tense form to indicate that the marriage occurred last year.
私は去年結婚しました。
I got married last year.
In this usage, '結婚' functions as a noun, representing the concept or institution of marriage as a significant choice in one's life.
結婚は人生の大切な決断です。
Marriage is an important decision in life.
Although '結婚' is part of the term '結婚式', which means 'wedding ceremony', the root noun still pertains to the concept of marriage, here specifying the event of the ceremony.