isobar
nounUK /ˈaɪsəʊbɑː/
US /ˈaɪsoʊbɑːr/
A line on a weather map that joins places with the same air pressure.
The isobars on the map are close together, so it will be windy today.
RELATED WORDS
OTHER MEANINGS
2. In physics, a line connecting points of equal pressure in a fluid or gas.
The engineer drew an isobar to show where the pressure stayed constant.
3. In nuclear physics, any of two or more atoms that have the same mass number but different atomic numbers.
Carbon-14 and nitrogen-14 are isobars because both have a mass number of 14.
4. A line on a chart joining places where a given quantity has the same value.
The isobar on the graph marks all points with equal rainfall.