the.com/redundancy

means The state of having extra, duplicate systems or personnel so that if one fails or is unneeded, another can take over — though it's also the awkward word for being laid off because your role was one of the duplicates.

from From Latin redundare, 'to overflow' — itself built from re- ('again') plus undare ('to surge like a wave'), from unda, 'wave.' Something redundant was originally just excessive, overflowing beyond what's needed — water sloshing past the brim. English borrowed that sense of superfluous overflow in the 1600s, and by the 20th century it had curdled into bureaucratic euphemism: a 'redundant' worker isn't fired, they're simply... surplus water.