1. A person or entity that has difficulty sleeping, experiences restless sleep, or does not achieve adequate sleep quality
He is someone who doesn't sleep well and often feels tired during the day.
Ele é alguém que não dorme bem e frequentemente se sente cansado durante o dia.
2. Characterized by insomnia, light sleep, or frequent awakenings during the night
She is that kind of person who doesn't sleep well due to stress.
Ela é aquele tipo de pessoa que não dorme bem por causa do estresse.