Chitin

The organic substance that makes up the exoskeleton of arthropods.

Came across this while I was look­ing up the def­i­n­i­tion of Cara­pace. I’d always assumed it was pro­nounced with a soft ch sound and a short i. In actu­al­i­ty it’s a hard ch and a long i. Instead of rhyming with kit­ten, it rhymes with Titan.