The best definition I've found for lyric poetry is the following excerpt from thoughtco.com. To read the entire article simply copy and paste the following link:
https://www.thoughtco.com/lyric-poem-definition-examples-4580236
Lyric Poetry: Expressing Emotion Through Verse
This musical verse conveys powerful feelings.
by Jackie Craven*
Updated December 07, 2019
A lyric poem is short, highly musical verse that conveys powerful feelings. The poet may use rhyme, meter, or other literary devices to create a song-like quality.
Unlike narrative poetry, which chronicles events, lyric poetry doesn't have to tell a story. A lyric poem is a private expression of emotion by a single speaker. For example, American poet Emily Dickinson described inner feelings when she wrote her lyric poem that begins, "I felt a Funeral, in my Brain, / And Mourners to and fro."
Key Takeways: Lyric Poetry - A lyric poem is a private expression of emotion by an individual speaker. Lyric poetry is highly musical and can feature poetic devices like rhyme and meter.Some scholars categorize lyric poetry in three subtypes: Lyric of Vision, Lyric of Thought, and Lyric of Emotion. However, this classification is not widely agreed upon.
*Jackie Craven, Doctor of Arts in Writing, has over 20 years of experience writing about architecture and the arts. She is the author of two books on home decor and sustainable design and a collection of art-themed poetry.