1. to lack energy, enthusiasm, or interest; to be sluggish or indifferent
After the long illness, she was listless and struggled to motivate herself.
Após a doença prolongada, ela estava apática e lutava para se motivar.
2. to show little or no interest in what is happening around you
The students were listless during the lecture and didn't participate.
Os alunos estavam desinteressados durante a aula e não participaram.