'preload' originates from the prefix 'pre-' (from Latin 'prae', meaning 'before') combined with the word 'load' (the modern form descending from Old English 'hladan', meaning 'to place on a load').

'preload' was formed in Modern English by compounding 'pre-' + 'load'; the compound became used in technical contexts (engineering, later computing) in the 20th century, and the derived noun 'preloading' followed.

Initially it could be understood literally as 'to place a load beforehand'; over time it acquired technical senses such as 'to apply initial tension' in mechanics and 'to load data/resources in advance' in computing.