citronellal
noun
cit·ro·nel·lal ˌsi-trə-ˈne-ˌlal 
: a lemon-odored aldehyde C10H18O that is derived especially from citronella oil and is used in perfumery and as an insect repellent
Example Sentences
Recent Examples on the Web Their oils contain at least 10 to 20 percent citronellal. 
Benjamin Whitacre, Better Homes & Gardens, 30 Aug. 2022
Benjamin Whitacre, Better Homes & Gardens, 30 Aug. 2022 Word History
Etymology
International Scientific Vocabulary, from New Latin citronella
First Known Use
1890, in the meaning defined above
Medical Definition
citronellal
noun
cit·ro·nel·lal -ˈnel-ˌal
: an aldehyde C10H18O with a lemony odor that is obtained especially from citronella oil and that is used in perfumery and as an insect repellent