hipojymnia, two corrections
heard as hipojymnia
spelled hypogymnia
Hypogymnia. Two corrections: hy at the front, g in the middle.
What the ear did
The second y has survived here, which is the unusual part. Most renderings lose that one first, because it sits next to the soft g and both change together.
H-Y-P-O-G-Y-M-N-I-A
The full entry for hypogymnia covers the name itself.