Final answer:
The meaning of the word "duck" cannot be determined without more context or explanations.
Step-by-step explanation:
The word "duck" can be understood through various clues. Clues can include context, definitions, and examples. In this case, since we only have the word "duck" and two question marks as clues, it is challenging to determine the meaning without any additional information. To understand what "duck" means, we would need more context or explanations provided.