A letter (capital Ð, small ð) introduced into Old English to represent its dental fricative, then not distinguished from the letter thorn, no longer used in English but still in modern use in Icelandic, the IPA and other phonetic alphabets to represent the voiced dental fricative "th" sound as in the English word then. The letter is also used in Faroese, but is generally silent in that language.
"The maintenance crew checked the eth systems on every locomotive before winter to ensure the trains wouldn't freeze in the depot."
Initialism of electric train heat/heating.
A short form of the female given name Ethel.
"Eth stopped by my desk to say hello, and I couldn't help but smile at how friendly she looked in her little blue dress."