This is the 576th most frequent Swedish word.
västra
"Västra" means "western" in English.
In this sentence, 'västra' functions as an adjective, describing 'delen' (the part) to specify which part of the city is being referred to.
Västra delen av staden är känd för sina vackra parker.
The western part of the city is known for its beautiful parks.
Here, 'västra' modifies the noun 'kusten' (the coast), indicating a specific geographic area.
Vi bor i en liten by på den västra kusten.
We live in a small village on the western coast.
In this example, 'västra' is used as part of a proper noun, 'Västra Götaland', indicating a specific name and thus functioning nominally.