keen

The word evokes a sense of "sharpness," whether that sharpness is physical, sensory, intellectual, or emotional. It suggests a high degree of intensity and precision. In the context of enthusiasm, it implies an active, eager drive rather than just passive interest. In British English, it is frequently used to describe someone who is very dedicated to a hobby or subject (e.g., "a keen gardener"). When applied to senses or blades, it describes a piercing quality—something that cuts through noise, scent, or material with ease. It is more refined than "strong" or "sharp," implying a superior level of sensitivity. As a verb, the tone shifts dramatically toward raw, visceral grief. This usage is rarer and carries a haunting, traditional connotation of public mourning and loud lamentation.