This is the 13147th most frequent Polish word.
oglądających
"Viewing" or "watching" (referring to people who are viewing).
In this sentence, 'oglądających' is used as a present participle in a plural form, indicating people who are currently engaged in watching something.
Oglądających koncert można było policzyć na palcach jednej ręki.
Those watching the concert could be counted on one's fingers.
Here, 'oglądających' refers to individuals in the act of watching and is used as a descriptive participle.
Film był tak nudny, że niewielu oglądających zostało do końca.
The movie was so boring that few viewers stayed until the end.
In this example, 'oglądającym' is in dative form, describing the audience of the exhibition to whom the leaflets are being given.