This is the 13226th most frequent Swedish word.
trean
"The third one" or "number three."
In this sentence, "trean" is used to refer to a specific bus line, namely line number three.
Jag tog trean till centrum idag.
I took the number three bus to the center today.
Here, "trean" refers to the card labeled as three in a deck of cards.
Det är trean på korten som jag har i handen.
It is the three card among the cards I have in my hand.
In this example, "trean" represents an apartment numbered three in a particular building.