Incubus (noun)

1. A demon in male form said to lie upon sleepers, especially women, in order to have sexual intercourse with them.
2. A male nightmare or a dream in which one is being sexually attacked.
3. A source of worry, stress or oppression that saps one's energy and strength.

Origin:

Derived from the latin word "incubo" meaning "nightmare".

Examples:

1. In medieval folklore, an incubus was thought to be a male demon that preyed upon sleeping women.
2. She suffered from frequent incubi, leaving her feeling exhausted and overwhelmed.
3. The financial stress of debt had become an incubus on their minds, affecting their daily lives.
4. The incubus of poverty and unemployment plagued the city's residents.
5. The incubus of poor health and medical bills hung over the family, causing them constant stress.