This is the 26th most frequent Danish word.
eller
"Or."
'eller' is used as a coordinating conjunction to present a choice between two options: coffee or tea.
Vil du have kaffe eller te?
Would you like coffee or tea?
'eller' is used to connect two alternative actions or suggestions in the sentence.
Vi kan tage bussen, eller vi kan gå.
We can take the bus, or we can walk.
'eller' is used to express a comparison or questioning between two possibilities.