Heard spelling

jineecium

Spelled gynoecium. two changes at once

How many letters can one word lose at once?

Three, in this case. The spelling is gynoecium.

Jineecium replaces the g with j, the y with i and the oe with ee. Each swap is defensible on its own. Stacked, they leave nothing of the Greek behind, and the Greek is the whole reason the word looks the way it does: gyne plus oikos, glued together with both halves keeping their own spelling.

Say

guy-NEE-see-um, and jy-NEE-see-um is heard just as often

Letters

G-Y-N-O-E-C-I-U-M