Nemoral

Say this adjective, repeatedly, quickly, enunciating each of the syllables, and allowing your tongue to do most of the work, I promise that you will first startle your neighbors, and second sound as though you've regressed back to kindergarten.

The OED accredits nemoral's most recent origins to the Latin word nemoralis "belonging to a wood or forest, frequenting woodland." The stem nemor-, nemus being a "cognate with ancient Greek  wood, Gaulish nemeton holy place (probably originally holy grove), Old Irish nemed holy place (OED)." 

Merely murmuring this word aloud makes it a little pet of mine, but the added pleasure of its definition referring to the forest as a holy place makes it all the more endearing.