1. (of animals) to chew cud; to regurgitate and chew again food that has been swallowed
Cows ruminate throughout the day.
As vacas ruminam durante todo o dia.
2. to think deeply about something; to ponder or meditate
She ruminated on the difficult decision for weeks.
Ela ruminava sobre a decisão difícil há semanas.
3. to go over something repeatedly in one's mind, often with worry or anxiety
He tends to ruminate on past mistakes.
Ele tende a ruminar sobre erros passados.