A Sonsfilian feather-lyre was a type of musical instrument.
History and specifications[]
In the year 2268, the sound of wind blowing through the leaves and tendrils of the plants on the planet Octavius IV reminded Captain James T. Kirk of a Sonsfilian feather-lyre. (TOS novel: Legacy)
- Presumably the descriptor "Sonsfilian" refers to a race or culture, or possibly a location such as a planet or planetoid.