silverfish

UK: /ˈsɪlvəˌfɪʃ/ US: /ˈsɪlvɚˌfɪʃ/ ,(sil′vər fish′)

Inflections of 'silverfish' (n):

silverfish

npl (Especially as a collective plural—e.g. "Silverfish are nocturnal insects.")

silverfishes

npl (Mainly used to talk about different types—e.g. "Silverfishes include the tarpon and the silversides.")

WordReference Random House Learner's Dictionary of American English © 2025

sil•ver•fish /ˈsɪlvɚˌfɪʃ/   n. [countable] , pl. (esp. when thought of as a group) -fish, (esp. for kinds or species) -fish•es. 

1. Fish any of various silvery fishes, such as the tarpon.
2. Insects a wingless, silvery-gray insect that feeds on starch and damages books, wallpaper, etc.

WordReference Random House Unabridged Dictionary of American English © 2025

sil•ver•fish  (sil′vər fish′), n., pl. (esp. collectively) -fish,  (esp. referring to two or more kinds or species) -fish•es. 

1. Fish a white or silvery goldfish, Carassius auratus.
2. Fish any of various other silvery fishes, as the tarpon, silversides, or shiner.
3. Insects a wingless, silvery-gray thysanuran insect, Lepisma saccharina, that feeds on starch, damaging books, wallpaper, etc.

• silver + fish 1695–1705

Collins Concise English Dictionary © HarperCollins Publishers::

silverfish / ˈsɪlvəˌfɪʃ/ noun ( -fish, -fishes)

1. a silver variety of the goldfish Carassius auratus
2. any of various other silvery fishes, such as the moonfish Monodactylus argenteus
3. any of various small primitive wingless insects of the genus Lepisma, esp L. saccharina, that have long antennae and tail appendages and occur in buildings, feeding on food scraps, bookbindings, etc: order Thysanura (bristletails)