Definition
A solution of salt (typically sodium chloride or calcium chloride) dissolved in water, used in some aircraft and ground-support systems as a heat-transfer fluid or as a freezing-point-depressed liquid for de-icing and refrigeration applications.
Plain English
Salty water. Because adding salt lowers the temperature at which water freezes, brine can stay liquid in cold conditions where plain water would turn to ice, which makes it useful in cooling systems and on icy surfaces.
Context Anchor
Seen in maintenance, cooling-system, and winter-operations discussions where salt-water mixtures may be mentioned.
Derivation
From Old English bryne, meaning salty water or a strong solution of salt. The word has carried the same basic meaning for over a thousand years; aviation simply borrows the term for any salt-and-water solution used in technical applications.
Why Pilots Care
Keeps aircraft movement areas free of ice so takeoffs, landings, and taxiing remain safe in freezing conditions.
Intuition Check
Brine does not mean any dirty, icy, or standing water. In this context, it means water with salt dissolved in it.
Example Sentence 1
The ground crew sprayed brine on the ramp before the freezing rain arrived to keep ice from bonding to the surface.
Example Sentence 2
The aircraft taxied without slipping after the ramp had been treated with brine.