John Keats was an English Romantic poet, notably remembered for his works such as 'Ode to a Nightingale' and 'Ode on a Grecian Urn'. He is often referred to as the 'ODIST' due to his mastery of the ode form of poetry. His works are still studied and admired today, and he is considered one of the most influential poets in the English language. The crossword solution 'ODIST' is a reference to Keats' poetic style.