This is the 868th most frequent Czech word.
trestu
"Penalty" or "punishment."
Here, 'trestu' ('of the punishment') is used in the context of referring to the act of carrying out a punishment.
Přesně si pamatuji, jaký pocit jsem měl při vykonání trestu.
I distinctly remember the feeling I had during the execution of the punishment.
In this sentence, 'trestu' ('of a punishment') describes the punishment in terms of its undue severity, showing a possesive relation to the noun.
Obával se nepřiměřeného trestu za svůj čin.
He feared an excessive punishment for his action.
Here the use of 'trest' ('punishment') provides the idea of retributive justice, illustrating its specific legal or ethical context.