eterälläkoonlys
Eterälläkoonlys is a term that appears to be a neologism or a portmanteau. A breakdown of the potential constituent parts suggests its meaning. "Eterä" is a Finnish word meaning "tough" or "durable." "Koon" could relate to "koon," the genitive form of "koko" in Finnish, meaning "size" or "extent." "Lys" is less clear, but in some contexts, it might suggest "light" or "illumination" (e.g., from "valo" meaning light, or "loiste" meaning gleam).
Therefore, "eterälläkoonlys" could be interpreted as a "tough, large-scale light" or a "durable, extensive illumination." Without