a colorless liquid, CHO, with a very strong lemon odor, found in lemons and eucalyptus oil, and used in perfumes and soaps
See citronellal in American Heritage Dictionary 4
(sĭtˌrə-nĕlˈălˌ)
noun
A colorless aromatic liquid, C10H18O, obtained from citronella and certain other essential oils or produced synthetically and used in making perfumes and as a commercial flavoring.