This is the 12066th most frequent Polish word.
lipcowych
"Related to July."
The word 'lipcowych' here acts as an adjective describing the events as occurring in July.
Udział w lipcowych wydarzeniach był obowiązkowy.
Participation in July events was mandatory.
In this sentence, 'lipcowych' modifies 'wakacji' to specify that these holidays took place in July.
Podczas lipcowych wakacji odwiedziliśmy góry.
During July holidays, we visited the mountains.
Here, 'lipcowych' qualifies 'kwiatów' to indicate that the flowers are associated with the month of July.