paling.

From Middle Dutch palinc, padelinc, paeldinc, from Old Dutch paelding, paleding, palezinc. The original form seems to be *palathing (attested in the placename Palathingadīc) or, as some sources prefer, *pathaling. This has no cognates outside Dutch and probably goes back to a substrate language. As the oldest attestation is (latinised) palengus, one could alternatively see the -th- as excrescent and thus derived the word from Proto-West Germanic *pāl (“pole”) after the fish's shape. While this is less likely, the distinction sometimes made between aal (“juvenile eel”) and paling (“large, adult eel”) may indeed have been influenced by association with paal.