This is the 371st most frequent Croatian word.
ivan
"Ivan" is a common Croatian male given name, equivalent to "John" in English.
'Ivan' is used here as a proper noun, referring to a person's name, specifically the subject of the sentence.
Ivan je došao kući rano.
Ivan came home early.
'Ivanom' is the instrumental case of the noun 'Ivan', used when discussing actions performed by or with someone.
Razgovarala sam s Ivanom o našim planovima.
I talked with Ivan about our plans.
'Ivanov' is the possessive form of 'Ivan', indicating ownership of the bicycle.