as keen as mustard Definition

mustard
noun

1. An annual plant native to Europe and W Asia, with bright yellow flowers.
2. A hot-tasting paste used as a condiment or seasoning, made from powdered or crushed whole seeds of black or white mustard or both, mixed with water or vinegar. Also as adj.

Example: mustard pot
3. A light yellow or brown colour.

adj

1. Having a light yellow or brown colour.

Idiom: as keen as mustard

colloq
Extremely keen or enthusiastic.

Etymology: 13c: from French moustarde, from Latin mustum must², which was originally an ingredient of the condiment.