In this study, a terminological and grammatical survey of essential and fatty oils of plant origin was performed in the selected Austrian, Hungarian, Spanish, and Belgian pharmacopoeias from the 18th to 19th centuries. The Latin-language prescriptions were analysed for their content, sections, and indications, and then translated from Latin into English, and supplemented with the source plants. Oil types were categorised based on their preparation and origin. Most oils belong to essential oils in Ph. Austriaca I–IV, Ph. Belgica, and Ph. Hungarica I (20 in each). Cooked oils are described as having the highest number in Ph. Hispanica (21), while pressed oils are also included in a high ratio in Ph. Hisp. (18) and Ph. Austriaca V (15). At the same time, those from minerals are described only in Ph. Belg. (2) and Ph. Hisp. (5). Latin terms are used in preparation methods, including the most concise descriptions in Ph. Austriaca V and Ph. Hg. I. This comprehensive study provides new linguistic data on the oils of herbs in the selected pharmacopoeias. Studies of essential oils have recently been progressing, and this analysis might help in understanding information from old pharmacopoeias.