This is the 13625th most frequent Russian word.
незаконнорожденной
Illegitimate (born out of wedlock).
Here, the word "незаконнорожденным" is used to describe someone's illegitimate status concerning their birth.
Он знал, что его происхождение ставилось под сомнение, так как он считался незаконнорожденным.
He knew that his origin was doubted because he was considered illegitimate.
In this sentence, "незаконнорожденных" functions as an adjective describing children who were born out of wedlock.
В старые времена незаконнорожденных детей часто обделяли правами.
In old times, illegitimate children were often deprived of rights.
In this example, "незаконнорожденной" describes a girl, emphasizing her status as being born outside of marriage.