This is the 11131st most frequent Polish word.
gigantycznej
"Enormous" or "gigantic."
In this sentence, 'gigantycznej' is used as an adjective in its genitive form to describe the 'mountain' (góra) as being extraordinarily large.
Widok gigantycznej góry zapiera dech w piersiach.
The sight of the gigantic mountain takes one's breath away.
Here, 'gigantycznej' is utilized as an adjective in its genitive form to emphasize the extremely large quantity of 'energy' (energia).
Projekt wymaga gigantycznej ilości energii.
The project requires a gigantic amount of energy.
In this usage, 'gigantycznej' functions as an adjective in its genitive form to highlight the immense nature of 'responsibility' (odpowiedzialność).