"Defenestration" is pronounced: deh-feh-nes-tray-shun
"Phobia" is a fear of something.
"Phobia" is pronounced: foh-bee-uh
Therefore, "defenestrationphobia" is pronounced: deh-feh-nes-tray-shun-foh-bee-uh
Breakdown:
* deh-feh - like "day" but with a shorter "a" sound
* nes - like "nest"
* tray-shun - like "treasure" but with a "sh" sound
* foh-bee-uh - like "hobby" with a "u" sound