The simple short answer to this is to look at the area of the section where the leader signs. In each of the handbooks, it clearly records what is required to complete the section the child is working on. In this case, it comes from Ultimate Challenge Book 1.
You can clearly see that to complete the section the clubber must recite the question and answer as well as recite the verse. Anything else in the section is not required to complete the section, though it is good to review it. Like definitions to help the child understand the verse.
The clubbers does not need to know the definitions to pass the section. They are there to help the clubber understand the verse they are learning and gives you a chance to see if they know the definition and explain the verse and why they are memorizing it. Remember that the clubber can receive two helps per section.