This is the 6946th most frequent Polish word.
gorlicach
"Gorlicach" is the locative case of "Gorlice," a town in Poland, used to mean "in Gorlice."
The word 'gorlicach' here is the locative case of 'Gorlice', a town's name, used because of the preposition 'w' indicating location.
W Gorlicach odbywa się festiwal muzyczny.
A music festival is taking place in Gorlice.
Once again, 'gorlicach' is in the locative case, used in this example due to 'w', showing location of residence.
Mieszkam w Gorlicach od pięciu lat.
I have lived in Gorlice for five years.
The word 'gorlicach' appears in the locative case, required by the scenario described with the preposition 'w' implying 'in Gorlice'.