This is the 8549th most frequent German word.
klotz
Block, log, or clod.
In this sentence, 'Klotz' is used to refer to a literal block of material, possibly wood or stone.
Der alte Klotz war schwer zu heben.
The old block was difficult to lift.
Here, 'Klotz' metaphorically describes a person who is emotionally unresponsive or stubborn.
Er benahm sich wie ein Klotz und reagierte überhaupt nicht.
He acted like a block and didn't react at all.
In this context, 'Klotz' is used figuratively to indicate something obstructive, potentially symbolizing a hindrance or difficulty.