This is the 4295th most frequent Dutch word.
blok
Block.
The word 'blok' is used to refer to a solid block of wood in this context.
Ik heb een blok hout nodig om het vuur aan te steken.
I need a block of wood to start the fire.
Here, 'blok' refers figuratively to a section or module of content within educational materials.
Het was een lastig blok in het lesmateriaal.
It was a tough block in the teaching material.
In this sentence, 'blok' describes a component of a bike, possibly referring to a mechanical part.