peor
worse
Peor means worse. It doesn't have any clear pieces to help remember it, but you can associate it with the English word 'poor' as a mnemonic device, thinking that something worse is often poorer in quality.
adjective
  1. worse
    Of the lowest quality or the most unpleasant, difficult, or severe
    Este es el peor día de mi vida. // This is the worst day of my life.
adverb
  1. worse
    To a more unpleasant, difficult, or severe degree
    Cada vez me siento peor. // I feel worse and worse.