crownwork

noun

1. (dentistry) dental appliance consisting of an artificial crown for a broken or decayed tooth"tomorrow my dentist will fit me for a crown"
2. a type of fortification, like a hornwork, but consisting of a full bastion with the walls on either side ending in half-bastions from which longer flank walls run back towards the main fortress."The crownwork was used to extend the fortified area in a particular direction often in order to defend a bridge, prevent the enemy occupying an area of high ground, or simply strengthen the overall fortifications in the expected direction of attack."