This is the 1456th most frequent Swedish word.
grekiska
"Greek" (the language).
In this sentence, 'grekiska' refers to the Greek language, denoting an academic study.
Jag lär mig grekiska på universitetet.
I am learning Greek at the university.
Here, 'grekiska' again refers to the Greek language, specifically someone's ability to speak it fluently.
Han talar flytande grekiska efter att ha bott där i flera år.
He speaks fluent Greek after living there for several years.
'Grekiska' is used to denote 'ancient Greek,' describing the language in a historical and scholarly context.