bartizan
noun
bar·ti·zan ˈbär-tə-zən 
ˌbär-tə-ˈzan
ˌbär-tə-ˈzan : a small structure (such as a turret) projecting from a building and serving especially for lookout or defense
Example Sentences
Recent Examples on the Web Your feudal lord did not have a range of mottes, baileys, bartizans, drawbridges, dungeons, machicolations and turrets to choose from. 
A-LIST, 2 Oct. 2017
A-LIST, 2 Oct. 2017 Word History
Etymology
alteration of Middle English bretasinge, from bretais parapet — more at brattice
First Known Use
15th century, in the meaning defined above