This is the 18th most frequent German word.
um
"Um" in German can mean "around," "at" (time), or "about," depending on context.
In this sentence, 'um' is used in combination with 'zu' to indicate purpose or intention.
Ich gehe nach oben, um zu lesen.
I go upstairs to read.
Here, 'um' is used as a preposition to indicate a spatial relationship, meaning 'around'.
Er wartet um die Ecke.
He is waiting around the corner.
In this instance, 'um' is used as a preposition to specify a point in time.