The term 'Horatian or Keatsian' refers to two different styles of poetry. Horatian poetry is characterized by its use of satire and wit, while Keatsian poetry is known for its romanticism and beauty. The crossword solution for this term is ODIC, which is an adjective meaning 'relating to or composed of verse'. This term is often used to describe the poetic works of both Horace and John Keats.