Which term refers to the breeding or spreading of something?

The term that refers to the breeding or spreading of something is "propagation." In a general sense, propagation is often used in various contexts such as botany, where it denotes the process of multiplying plants, whether through seeds, cuttings, or other methods. In a broader context, propagation can also indicate the spreading of ideas, beliefs, or cultural practices, illustrating its versatile application across different fields.

The other terms do not relate to the concept of breeding or spreading. "Pugilist" specifically refers to a boxer or someone who fights, and does not imply any sort of breeding or spreading. "Pucker" is related to the action of wrinkling or contracting, often in relation to the mouth or skin, while "profuse" describes something that is abundant or plentiful but does not inherently relate to the act of breeding or spreading. Thus, "propagation" is the most appropriate term for this definition.