vigour

Vigour, or vigor in American English, refers to physical or mental energy, stamina, and the drive behind action. It can describe the liveliness of a person, the force of effort, or the robustness of a process. In everyday use, vigour implies spirited vitality and resilience; in more specialized contexts, it may denote measurable capacity to perform work or withstand stress.

Etymology traces vigour to Old French vigueur and Latin vigor, meaning activity or force. The spelling vigour is standard in British English, while vigor is preferred in American English, though both terms share the same core sense.

In physiology and psychology, vigour relates to vitality, arousal, and motivation. It is distinct from mood but interacts with it; higher vigour often accompanies readiness to engage in demanding tasks. In clinical or performance contexts, assessments may consider energy levels, endurance, and the ability to sustain effort.

In botany and agronomy, vigour has a technical meaning: seed vigour describes a seed’s potential for rapid, uniform germination and robust growth under adverse conditions. Plant breeders seek higher vigour to improve crop establishment and yields. Terms such as growth vigour and vigor index appear in research to summarize germination performance and early development.

Culturally, vigour can carry normative associations with youthful energy, athleticism, or moral vitality. Across disciplines, the concept centers on the capacity to exert force, endure effort, and maintain performance across tasks or environments.