Foli
/ˈfəʊ.laɪ/noun
A plural form of folium, referring to leaflike structures, especially in anatomy, botany, and geology.
Did you know?In scientific language, folium preserves the ancient metaphor that a thin, layered structure resembles a leaf—even when it appears in the brain or in mineral formations.
Etymological Timeline
Proto-Indo-European
PIE
*bhel-
“To swell, expand, or unfold; a reconstructed root associated with leaf growth and forms.”
Ancient Greek
Greek
phýllon
“Leaf; foliage.”
Classical Latin
Latin
folium
“Leaf, leaf-shaped object, or sheet of writing material.”
Medieval Latin
Latin
folia
“Leaves or leaflike structures; the plural of folium.”
19th Century
Scientific English
foli
“A technical plural used for leaflike structures in scientific terminology.”
Modern English
English
foli
“Plural of folium, especially in anatomy, botany, and geology.”
Explore more surprising origins