Polar describes something related to the North or South Pole, the icy regions at the very top and bottom of Earth. Polar bears live in the Arctic polar region, while penguins waddle across the Antarctic polar ice. These polar regions experience extreme cold and long periods of darkness in winter, followed by months of continuous daylight in summer.

Scientists use polar to describe this unique climate and environment. A polar expedition means traveling to these frozen ends of the Earth, which requires special equipment and careful planning. The word captures both a geographic location and the harsh, icy conditions found there.

In science and mathematics, polar takes on additional meanings. In chemistry, a polar molecule has an uneven distribution of electrical charge, like water molecules that stick together because one end is slightly positive and the other slightly negative. This property explains why oil and water don't mix: oil molecules are nonpolar.

In mathematics, polar coordinates describe the location of a point using distance and angle rather than up-down and left-right measurements, which proves especially useful for describing circular or rotating motion.

The word also appears in the phrase polar opposites, meaning two things that are as different as possible, like hot and cold or day and night.