Old English æl "eel," from Proto-Germanic *ælaz (source also of Old Frisian -el, Middle Dutch ael, Dutch aal, Old Saxon and Old High German al, German Aal, Old Norse all), which is of unknown origin, with no certain cognates outside Germanic. Used figuratively for slipperiness from at least 1520s.
Old English fær "journey, road, passage, expedition," from strong neuter of faran "to journey" (see fare (v.)); merged with faru "journey, expedition, companions, baggage," strong fem. of faran. Original sense is obsolete, except in compounds (wayfarer, sea-faring, etc.) Meaning "food provided" is c. 1200 (Old English also had the word in the sense "means of subsistence"); that of "conveyance" appears in Scottish early 15c. and led to sense of "payment for passage" (1510s). Meaning "person conveyed in a vehicle" is from 1560s.
<a href="https://www.etymonline.com/word/elver">Etymology of elver by etymonline</a>
Harper, D. (n.d.). Etymology of elver. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/elver