suero
/ˈsweɾo/ · B2 · noun · m
serum
💉 suero = sounds like 'SWAIR-oh' – the clear fluid dripped in a hospital line
Spanish suero comes from Latin serum, meaning watery fluid. Whey is the watery part left after milk curdles, and the same idea covers blood serum and the saline fluid in an IV drip.