make feel weak or without energy
enervate - weaken
If something ‘enervates’ a person, it weakens them or saps their energy. This is typically due to something being tedious or physically or mentally exhausting. It is a formal word that is always used in a negative context.
Being out in the hot sun all day was more than enough to enervate me. I need a lie-down!
Working long hours can be financially rewarding, but after a while, it can lead to a sense of enervation.
Her speech was so boring and long-winded that it managed to enervate every person in the room.