sapping

This term describes a slow, draining process rather than a sudden loss of power. When used as an adjective, it carries a heavy, oppressive connotation, often associated with environmental factors like extreme heat or emotional burdens like grief that erode a person's capacity to function over time.

In a military context, the term refers to a specific engineering tactic of undermining walls. This technical usage is distinct from the metaphorical sense of emotional or physical exhaustion, though both share the core concept of creating a void or weakness to cause a collapse.