This is the 110th most frequent Icelandic word.
börn
"Children."
In this sentence, 'börnin' is the definite plural form of 'börn', meaning 'the children', used here as the subject of the sentence.
Börnin leika sér úti í garðinum.
The children play outside in the garden.
Here, 'börn' refers to children in general and is in its indefinite plural form, directly linked to the possessive plural 'ættingjanna okkar' (our relatives).
Við skulum fara að heimsækja börn ættingjanna okkar.
We should go visit the children of our relatives.
'Börn' is used in its indefinite plural form to refer generally to children within the specified age range.