Final answer:
Blight means to cause something to suffer devastation, often used in reference to plant diseases or areas in economic decline.
Step-by-step explanation:
The correct definition of the word blight in the context given is option 3) cause to suffer devastation. The term blight is most often used in relation to plants, indicating a disease that causes them to wither or prevents them from growing. However, blight can also refer to anything that severely damages, deteriorates, or destroys. For example, a city suffering from economic decline might be described as being 'blighted' by poverty and unemployment.