opopanax UK /əˈpɒpənaks/US /əˈpɑpənæks/ noun3 •A perfume made from the gum resin of various trees.they were hit by a strong polyaromatic gust [...] which included alcohol fumes, tobacco and hemp-smoke, a spectrum of inexpensive scent in which opopanax and vervain figured prominently — 2006 •The popinac or opopanax tree (Acacia farnesiana, syn. Vachellia farnesiana), an acacia of America. •A gum resin obtained from the root of Opopanax chironium, formerly used in medicine. formsopopanaxes