carapace

1. N-COUNT A carapace is the protective shell on the back of some animals such as tortoises or crabs. (龜、蟹等的)甲殼[正式]

2. N-COUNT You can refer to an attitude that someone has in order to protect themselves as their carapace. 保護殼[文學性] [usu with supp]

The arrogance became his protective carapace. 傲慢成了他的保護殼。