Wiktionary
oleanolic acid
n. (context organic compound English) A pentacyclic triterpenoid carboxylic acid found in many plants; an isomer of ursolic acid
Wikipedia
Oleanolic acid
Oleanolic acid or oleanic acid is a naturally occurring pentacyclic triterpenoid related to betulinic acid. It is widely distributed in food and plants where it exists as a free acid or as an aglycone of triterpenoid saponins.