a. Chem. Also usneic. [f. USN-EA + -IC 1 b.] Usnic acid, carbusnic acid; usnin.
1847. W. Gregory, Handbk. Org. Chem. (ed. 2), 502. Usnic Acid … is found in many lichens,… and in many species of Usnea [etc.].
1848. Fownes, Elem. Chem. (ed. 2), 514. The Usnea barbata and several other lichens contain usneic acid.
1861–7. [see USNIN].
