This is the 321st most frequent Icelandic word.
eyjar
"Eyjar" means "islands" in English.
Here, "eyjar" is used to refer to islands collectively as plural.
Eyjar eru umkringdar sjó.
Islands are surrounded by the sea.
In this sentence, "eyjar" is used in the accusative plural form to indicate islands as the object of the sentence.
Ég hef heimsótt margar eyjar í sumar.
I visited many islands this summer.
This usage positions "eyjum" as the dative plural form, signifying the object of an action or preposition.