¹ Source: wiktionary.com
Medical Definition of Essential oils
1. Plant products, usually somewhat volatile, giving the odours and tastes characteristic of the particular plant, thus possessing the essence, e.g., citral, pinene, camphor, menthane, terpenes; usually, the steam distillates of plants or oils of plants obtained by pressing out the rinds of a particular plant. See: volatile oil. (05 Mar 2000)