1. (n.) Bark, as of a tree; hence, an outer covering.

2. (n.) Bark; rind; specifically, cinchona bark.

3. (n.) The outer or superficial part of an organ; as, the cortex or gray exterior substance of the brain.

armature armor armor plate bark body armor border buckler bulletproof vest chain armor chain mail chitin circumference coat of mail cork covering crust elytron envelope epicarp epidermis episperm exterior external facade face facet fringe front habergeon harness hauberk integument lineaments lorica lorication mail needles outer face outer layer outer side outer skin outline outside panoply peel peeling pericarp periphery phellum plate plate armor protective covering rind scute scutum shell shield skin spines suit of armor superficies superstratum surface test testa thick skin top