This is the 86th most frequent Icelandic word.
sú
The Icelandic word "sú" means "that" (feminine singular) or "the" (feminine singular definite article).
'Sú' as a demonstrative pronoun referring to a specific feminine noun.
Sú stelpa er mjög skemmtileg.
That girl is very funny.
'Sú' as a demonstrative introducing a relative clause referring to a feminine noun.
Ég tók sú ávöxt sem mér fannst bestur.
I took the fruit that I liked the most.
'Sú' as a demonstrative pronoun emphasizing a feminine noun in superlative form.