Likely related to South Asian and Arabic forms meaning romantic, poetic, or pomegranate-like.
Rumanii draws its roots from the Arabic word "rumman" (رمان), meaning pomegranate — one of the most symbolically charged fruits in human civilization. The pomegranate appears in the Hebrew Bible as a symbol of the Promised Land, in Greek myth as the fruit that bound Persephone to the underworld and gave the world its seasons, in Islamic art and architecture as a motif of paradise and abundance, and in Persian literature as an emblem of fertility, wisdom, and the multiplicity of life. To name a child after this fruit is to give them one of humanity's oldest symbols of renewal.
The Swahili adaptation "rumani" (with "rumanii" as a doubled, emphatic or dialectal form) entered the East African naming vocabulary through the same Arabic-Islamic cultural exchange that shaped so much of coastal Swahili civilization. In this tradition, the name carries all of the pomegranate's symbolic weight — abundance, hidden sweetness, the idea that a single exterior conceals multitudes within. It is a name that suggests depth and generosity, the promise of more than what first meets the eye.
The doubled final "i" in Rumanii gives the written name an unusual visual character and a slightly different sonic weight — a name that announces itself with emphasis. For families connected to East African, Arabic, or Persian traditions, Rumanii is a name that bridges those worlds elegantly, while for families drawn to it from outside those traditions, it offers entry into one of the world's richest symbolic vocabularies through the simple, beautiful vehicle of a fruit.