essence [LME] Essence comes via Old French from Latin essentia, from esse ‘to be’. An early meaning was ‘being, existence’. In alchemy it was used in the phrase fifth essence or *quintessence. Alchemists believed this substance to be latent in all bodies and thus to be extractable by distillation: this probably led to essence’s use for ‘an extract obtained from a plant with therapeutic qualities’, reinforced by the sense ‘indispensable quality or constituent’.