This is the 812th most frequent Ukrainian word.
людиною
The Ukrainian word "людиною" means "a person" or "a human" (instrumental case).
Here, "людиною" in instrumental case accompanies "допитливою" to denote a specific characteristic or attribute.
Вона вирізняється серед інших своєю допитливою людиною.
She stands out among others with her inquisitive personality.
In this example, "людиною" is again instrumental case form, indicating the continuing state of being a kind individual.
Після всього, що вони пережили, він лишився доброю людиною.
After everything they went through, he remained a kind human being.
The word "людиною" is used as an instrumental case form of the noun "людина" (human, person), describing a quality or state associated with the subject.