This is the 11146th most frequent Polish word.
gnębiących
"Oppressing" or "harassing."
Here, 'gnębiących' functions as an attributive present participle, describing the boys who are actively causing distress.
Gnębiących chłopców zabrano do dyrektora.
The bullying boys were taken to the principal.
In this case, 'gnębiących' is used as an attributive present participle, modifying 'sytuacji' to describe situations that are oppressive or distressing.
Widok gnębiących sytuacji wywołał smutek.
The sight of oppressive situations caused sadness.
'Gnębiących' here is a substantive participle, a nominalized form referring to people who oppress or harass.