This is the 7620th most frequent Russian word.
енин
"Енин" is a Russian surname and does not have a standalone definition in English.
'Енин' here is used as a proper name to identify a character.
В книге был рассказ про героя с именем Енин.
In the book, there was a story about a hero named Yenin.
'Енисей' is the name of a river (proper noun) and uses 'енин' within it.
Енисей — одна из крупнейших рек в России.
The Yenisei is one of the largest rivers in Russia.
'енин' here describes characteristics (adjective form) related to a hypothetical or named person 'Енин'.