This is the 4731st most frequent Japanese word.
未婚
Unmarried.
The word "未婚" is used as an adjective to describe someone's marital status.
彼女はまだ未婚です。
She is still unmarried.
Here, "未婚" is used in a nominalized form "未婚の" to describe the condition of being unmarried.
未婚の状態で子供を育てています。
She is raising children while being unmarried.
In this sentence, "未婚である" functions as a predicate to emphasize the state of being unmarried.