This is the 3703rd most frequent Spanish word.
peores
Worse.
Here, 'peores' is used as an adjective to describe 'semanas' (weeks), indicating that they are the ones of lowest quality or most unfavorable within a comparison.
Estas son las peores semanas que hemos experimentado.
These are the worst weeks we have experienced.
In this sentence, 'peores' functions as an adjective modifying 'resultados' (results), emphasizing the extreme quality of inadequacy of the results in a comparative context.
Los peores resultados en el examen fueron inesperados.
The worst results in the exam were unexpected.
Here, 'peores' is an adjective describing 'errores' (mistakes), referring to those that are considered most severe or significant in their negative impact.