- Portuguese: Enguia, Eiró
- Spanish: Anguila
- French: Anguille
- Dutch: Aal, Paling
- German: Aal, Flussaal
- Polish: Wegorz
- Russian: Ugor’
- Finnish: Ankerias
- Swedish: Ål
- Norwegian: Ål
- Danish: Ål
- Icelandic: Áll
- Other: Eascú (Irish); Llysywen (Welsh); Anweye (Walloon)
Maximum length 135 cm. A specimen of this size would weigh 9 kilos. But this is exceptional. The usual adult size is much less and the British record for an eel caught by rod is less than 4 kilos.
Colour varies. Adults are usually black, greenish black or grey-brown on back and sides and yellowish below. Sides and belly become bright silver when the eel approaches sexual maturity and sets off to spawn (see below).