acreopan : spiders
The Illunse word for spiders (nominative plural) is acreopan. Acreopan is similar to two words in some real estate ads, acre + open.
Spiders in Latin is aranei or araneae. Spiders in Old English is átorcoppan.
Spider in Illunse is acreopa, which is a mix of the Latin word (araneus or aranea) and the Old English word (átorcoppe).
Here's a link to Spider, in J.R.R. Tolkien's words.