trit.

The answer suggested is that there were anciently seven strings, and that Terpander left out the Trit and added the Nt.

Triticum, trit′i-kum, n. a genus of grasses including the varieties of wheat.

“We will put these on Trit and Trot,” she said, drawing out two white skirts from her collection of doll clothes.

She now resolved to clutch at the first branch within reach, hoping in that way to scramble to safety with Trit.

But Trit also is doubtless originally the 'third string' rather than the 'third note.'