This is the 4823rd most frequent Swedish word.
barnoin
The word "barnoin" does not exist in Swedish.
Here, 'barnet' is used as 'child', a singular noun referring to one young person.
Barnet sprang runt på gården.
The child ran around the yard.
In this sentence, 'barn' means 'children', used as a plural noun to denote multiple young individuals.
Jag såg många barn spela fotboll.
I saw many children playing football.
Here, 'barndomen' refers to 'childhood', used as a noun that denotes the period of being a child.