Final answer:
The word 'chaff' primarily means the husks of grains separated during threshing, but metaphorically, it can mean something akin to rubbish. Option 1) Rubbish is the correct definition in the given context.
Step-by-step explanation:
The word 'chaff' can have a couple of meanings depending on the context in which it's used. In an agricultural sense, chaff refers to the husks of grains and grasses that are separated during the threshing process.
However, when used metaphorically, it often means something of little value, akin to rubbish or worthless material, particularly when separating valuable things from worthless ones. In this sense, it's similar to separating wheat from chaff. However, in the choices provided, the closest definition to 'rubbish' would be the correct one, making option 1) the most suitable answer.