'silver' originates from Old English, specifically the word 'seolfor', where 'seolfor' meant 'silver (the metal/color)'; 'fish' originates from Old English, specifically the word 'fisc', where 'fisc' meant 'fish (the aquatic animal)'. The compound 'silverfish' combines these elements to describe the insect's silvery, fish-like appearance.

'silver' changed from Old English 'seolfor' to Middle English 'selver' and eventually became the modern English 'silver'; 'fish' changed from Old English 'fisc' to Middle English 'fish' and then to modern 'fish'. The compound name 'silverfish' was formed in Modern English to name the insect.

Initially, it referred to an animal with a silvery, fish-like appearance; over time it became the established common name for the specific wingless household insect now called 'silverfish'.