This is the 10843rd most frequent Polish word.
dzisiejszego
"Of today's" or "of this day."
The word "dzisiejszego" in this context serves as a possessive adjective referring to "today's" related to the noun "spotkania" (meeting).
Podczas dzisiejszego spotkania omówimy ważne tematy.
During today's meeting, we will discuss important topics.
Here, "dzisiejszego" functions similarly as an adjective describing "wykładu" (lecture), indicating its relation to the current day.
Uczniowie szczególnie polubili teksty z dzisiejszego wykładu.
The students particularly liked the texts from today's lecture.
In this sentence, "dzisiejszego" modifies "treningu" (training), specifying that the training occurred on the present day.