Definition

Noun: A yellow, volatile essential oil obtained from the root of the costus plant (Saussurea costus or Saussurea lappa), primarily used as a fixative in perfumery.

Usage

"Costus oil" is used as a singular, uncountable noun. It refers specifically to the extracted oil itself. - The perfumer added a few drops of costus oil to the blend. - Costus oil has a distinctive, long-lasting woody and earthy aroma.

Advanced Usage

• In Aromatherapy: While its primary use is in perfumery, costus oil is sometimes mentioned in historical or traditional contexts of aromatherapy for its grounding scent, though it is not a common modern therapeutic oil due to potential sensitization.
• As a Fixative: In perfumery, a fixative is a substance that slows the evaporation of the more volatile top and middle notes. Costus oil is valued for this property.
  • The formula relied on costus oil to fix the delicate floral notes.

Variants and Related Words

• Costusroot / Costus Root (noun): The dried root of the costus plant from which the oil is distilled.
• Saussurea oil (noun): A less common synonym for costus oil, derived from the plant's botanical genus name.

Synonyms

• Costus essential oil
• Saussurea costus oil

Notes on Meaning

The term refers exclusively to the essential oil. It does not refer to other products derived from the costus plant, such as its root powder or extracts made with other solvents. Its key characteristics are its yellow color, volatility, and origin from the specific plant root.

Noun

1. a yellow volatile essential oil obtained from costusroot; used in perfumes