The meaning of the name Eilir is Butterfly. The origin of the name Eilir is Welsh. This is the culture in which the name originated, or in the case of a word, the language. People who like the name Eilir also like: Eira, Cassia, Imogen, Kiva, Aria, Ceri, Niamh. Cole, Liam, Anson, Egan, Aaron, Milo, Rafe.