This is the 422nd most frequent Hungarian word.
oka
"Reason" or "cause."
Here, 'oka' serves to specify the cause of 'misunderstanding,' demonstrating usage in a possessive form.
A probléma az oka a félreértésnek.
The problem is the cause of the misunderstanding.
In this example, 'oka' identifies the cause or motive for 'delay,' and is used in a similar possessive structure.
Nem tudom, mi az oka a késésednek.
I do not know the reason for your delay.
In this sentence, 'oka' is used in the nominative case to denote the reason or cause for the happiness.