Battlements

Concise Bible Dictionary:

2. netishoth: this signifies “expansion,” and may well refer to extended battlements. A parapet on the walls, with holes through which arrows could be shot, may be seen on some of the Assyrian monuments (Jer. 5:1010Go ye up upon her walls, and destroy; but make not a full end: take away her battlements; for they are not the Lord's. (Jeremiah 5:10)).
 
Jerusalem City Wall

From Manners and Customs of the Bible:

Deuteronomy 22:88When thou buildest a new house, then thou shalt make a battlement for thy roof, that thou bring not blood upon thine house, if any man fall from thence. (Deuteronomy 22:8). When thou buildest a new house, then thou shalt make a battlement for thy roof, that thou bring not blood upon thine house, it any man fall from thence.
The roofs of Eastern houses are flat, having a slight declivity from the center. As they are used for a variety of purposes by day, and often for sleeping at night (1 Sam. 9:2626And they arose early: and it came to pass about the spring of the day, that Samuel called Saul to the top of the house, saying, Up, that I may send thee away. And Saul arose, and they went out both of them, he and Samuel, abroad. (1 Samuel 9:26)) it becomes necessary to guard them by means of a wall. Almost every Eastern house has a parapet, the Moslems making theirs very high, to screen their women from observation.
The houses of Christians are sometimes built without parapets, and serious accidents occur. Dr. Shaw describes the battlements on the roofs of the houses in Barbary as very low on the side next the street, and also when they make partitions from the roofs of neighbors. He says of this outside wall that it is “frequently so low that one may easily climb over it” (Travels, p. 210). He also states that the inside parapet, next to the court of the house, is always breast high. There is sometimes here only a balustrade or lattice-work. In Syria, however, the higher battlement is next to the street, and the lower one next to the court.

Related Books and Articles:

201. Battlements