This is the 26th most frequent Icelandic word.
eins
"eins" in Icelandic means "one" or "as" (depending on context).
Here 'eins' is used as part of the phrase 'eins og', which functions as a comparison, similar to 'like' or 'as' in English.
Hún er eins og systir mín.
She is like my sister.
In this sentence, 'eins og' means 'as', indicating the manner in which an action is performed.
Allir gera eins og þeir vilja.
Everyone does as they wish.
'Eins...og' here is used for making an intensity comparison, meaning 'as...as' in English.