hypagymnia: is the prefix hypa- or hypo-?
heard as hypagymnia
spelled hypogymnia
Hypo-, meaning under. Hypogymnia.
What the ear did
The o of the prefix takes no stress, so the mouth flattens it and the ear reports something between a and u. The prefix is fixed across the whole language: hypothesis, hypotenuse, hypoxia, all with o.
H-Y-P-O-G-Y-M-N-I-A
The full entry for hypogymnia covers the name itself.