This is the 17674th most frequent Polish word.
zmarnować
To waste.
The word "zmarnować" is used here to mean 'to waste' in context of an opportunity, implying not utilizing it fully.
Nie chcę zmarnować tej okazji, aby z tobą porozmawiać.
I don't want to waste this opportunity to talk with you.
Here, "zmarnować" is utilized to indicate 'wasting' time, showing an unproductive use of time.
On zmarnował dużo czasu grając w gry komputerowe.
He wasted a lot of time playing computer games.
In this sentence, "zmarnować" means 'to waste' referring to resources, emphasizing the idea of conservation.