This is the 7331st most frequent Japanese word.
五十嵐
"五十嵐" (Igarashi) is a Japanese surname meaning "swift current" or "fifty storms."
In this sentence, "五十嵐" is used as a surname to refer to an individual.
五十嵐さんは親切な人です。
Mr. Gojira is a kind person.
Here, "五十嵐" is used to denote the family name of a group or household.
五十嵐家には犬が三匹います。
The Gojira family has three dogs.
In this context, "五十嵐" identifies an academic professional by their surname.