SYNONYMY NOTE: irritable implies quick excitability to annoyance or anger, usually resulting from emotional tension, restlessness, physical indisposition, etc.; , irascible, choleric are applied to persons who are hot-tempered and can be roused to a fit of anger at the slightest irritation; , splenetic suggests a peevish moroseness in one quick to ...
Quick Answer. A map direction symbol is called a compass rose, and a simple compass rose symbol may only depict the four cardinal directions of north, east, west and south. A compass rose has been used on charts, atlases and maps by navigators since the 14th century. A more detailed compass rose can show many other directions.
The compass is showing you what direction the magnetic field is in, so you can use the right hand rule to work out whether the current is flowing north to south or south to north. There's a good diagram of the magnetic field around a wire here.