This is the 9196th most frequent Spanish word.
abra
A mountain pass, clearing, or open space.
In this sentence, 'abra' refers to a geographical feature, a pass or opening in the mountains.
La abra en las montañas permite el paso entre los valles.
The mountain pass allows transit between the valleys.
Here, 'abra' is a verb in the subjunctive mood, present tense, of 'abrir' meaning 'to open'.
Cuando alguien abra la puerta, veremos quién está afuera.
When someone opens the door, we will see who is outside.
In this case, 'abra' denotes an opening or gap, emphasizing the concept of space being made.