An ancient Greek musical instrument, having (usually) seven strings and resembling a cithara or lyre.
The phorminx was traditionally used as an accompaniment to singing. The player plucked the strings directly with the left hand, and with a plectrum using the right hand..
Origin
Late 18th century; earliest use found in Charles Burney (1726–1814), musician and author. From ancient Greek ϕόρμιγξ lyre, of unknown origin, perhaps a loanword; with the suffix compare ancient Greek σάλπιγξ, σῦριγξ.