From the passage provided, extract Tagore's nickname

Context: The name Tagore is the anglicised transliteration of Thakur. The original surname of the Tagores was Kushari. They were Pirali Brahmin originally belonged to a village named Kush in the district named Burdwan in West Bengal. The biographer of Rabindranath Tagore, Prabhat Kumar Mukhopadhyaya wrote in the first volume of his book Rabindrajibani O Rabindra Sahitya Prabeshak that

The Kusharis were the descendants of Deen Kushari, the son of Bhatta Narayana; Deen was granted a village named Kush by Maharaja Kshitisura, he became its chief and came to be known as Kushari.

Life and events
Early life: 1861–1878
Main article: Early life of Rabindranath Tagore

Young Tagore in London, 1879
The last two days a storm has been raging, similar to the description in my song—Jhauro jhauro borishe baridhara a hapless, homeless man drenched from top to toe standing on the roof of his steamer the last two days I have been singing this song over and over as a result the pelting sound of the intense rain, the wail of the wind, the sound of the heaving Gorai River, have assumed a fresh life and found a new language and I have felt like a major actor in this new musical drama unfolding before me.

— Letter to Indira Devi.
The youngest of 13 surviving children, Tagore was born on 7 May 1861 in the Jorasanko mansion in Calcutta, the son of Debendranath Tagore and Sarada Devi.

Black-and-white photograph of a finely dressed man and woman: the man, smiling, stands with the hand on the hip and elbow turned outward with a shawl draped over his shoulders and in Bengali formal wear. In front of him, the woman, seated, is in elaborate dress and shawl; she leans against a carved table supporting a vase and flowing leaves.
Tagore and his wife Mrinalini Devi, 1883
Tagore was raised mostly by servants; his mother had died in his early childhood and his father travelled widely. The Tagore family was at the forefront of the Bengal renaissance. They hosted the publication of literary magazines; theatre and recitals of Bengali and Western classical music featured there regularly. Tagore's father invited several professional Dhrupad musicians to stay in the house and teach Indian classical music to the children. Tagore's oldest brother Dwijendranath was a philosopher and poet. Another brother, Satyendranath, was the first Indian appointed to the elite and formerly all-European Indian Civil Service. Yet another brother, Jyotirindranath, was a musician, composer, and playwright. His sister Swarnakumari became a novelist. Jyotirindranath's wife Kadambari Devi, slightly older than Tagore, was a dear friend and powerful influence. Her abrupt suicide in 1884, soon after he married, left him profoundly distraught for years.

Answer: Rabi