A latin word rougly translated to leisure. Otium means to set aside your political life or career gains in pursuit of activities that progress the soul. Activities such as writing, reading, philosophy, sports, solitude, and bathing (Romans love to bathe).
It was important to the Romans to balance otium (leisure) and negotium (business and daily affairs).
Perhaps, it isn’t suprising that the Romans are one of the most advanced civilizations in history. Conquering most of the known world and creating art still renowned to this day.