kumulativního
Kumulativního is the genitive singular form of the Czech adjective "kumulativní," which translates to "cumulative" in English. In essence, it refers to something that is accumulating or building up over time. When used in a sentence, "kumulativního" indicates possession or a relationship to something that is in a state of cumulative growth or accumulation.
For example, "účinek kumulativního" would translate to "the effect of the cumulative" or "the cumulative effect."