The sentence is the following: «Volverse derezoso es el modo de permitir el deterioro de la virtude.» I tried looking for the meaning, but I didn't find one. I think this is probably a typo, and they might want to say "perezoso". Am I right?
Might be a typo and be
perezoso, as you are suggesting. There's another typo with
virtude which should be
I checked to see in ancient forms of Spanish if the word was pronounced or spelled like that, and I couldn't find anything, so I'm positive that is a typo.
I guess that now that is clarified that it is indeed perezoso, it is clear that in that context it means that if you let yourself be lazy, you are going to allow your good qualities to go to waste (you would not take care of things because you are not focusing on them).