The verb gaslight is an interesting example of a compound word that has no semantic, or even metaphorical, correspondence with the concept it represents. It’s in fact named after the 1944 film Gaslight (starring Ingrid Bergman and based on an earlier stage play), in which a husband slowly convinces his wife she is going mad by claiming that she is just imagining that the house lights are flickering, when in fact he is turning on lights in the attic, thereby reducing the gas flow to the rest of the house and causing the quite real flickering of the downstairs lights.