buffer
n. countablen. something that protects you by acting as a shield or a cushion between two things. It can be a physical object, extra time, or even money saved for an emergency.
n. a person or thing that reduces a shock or forms a barrier between incompatible or antagonistic entities. Often used metaphorically in finance or social contexts to describe a protective margin.
I keep some extra money in my account as a buffer.
The trees act as a natural buffer between the noisy highway and the quiet residential neighborhood.
Economists argue that maintaining a significant capital buffer is essential for banks to withstand sudden market volatility without requiring a government bailout.
From buff + -er.
Agent noun from obsolete verb buff (“make a dull sound when struck”) (mid-16c.), from Old French buffe (“blow”). The “boatswain's mate” sense is said to be popularly explained by the mate being a “buffer”, that is intermediary, between officers and men, but various other explanations have also been proposed.
In reference to buff leather.
Often followed by the preposition 'between' or 'against'.