Based on the structure and hints provided, it seems like you're setting up an engaging word association quiz. Let's dive into the challenge and see if we can crack the code!

First Word Hint:

• This word is used in common for all meanings.

Given this hint, it suggests that the word we're looking for is a versatile term that fits into various contexts. Let's think about words that could fit this description.

Second Word Hint:

• Shall we demonstrate great reasoning skills like a detective?

This hint implies that the word might be related to solving mysteries or using logic. Words like "clue," "evidence," or "solve" come to mind.

Third Word Hint:

• If it's still difficult, I'll explain the meaning of the word.

This hint doesn't give us a new word but suggests that further clarification will be provided if needed.

Since we haven't guessed the word yet, let's look at the meaning hints:

First Meaning Hint:

• Hints have hints for word hints and meanings.

This suggests that the word could be related to guidance or assistance.

Second Meaning Hint:

• First, look at the word hints one by one and enter the correct answer if there is a word that comes to mind.

This hint reinforces the idea of a step-by-step process, perhaps indicating a word related to method or approach.

Third Meaning Hint:

• If you have seen all the word hints and do not know the correct answer, try opening the meaning hints one by one.

This hint reiterates the process of using hints to solve the puzzle.

Fourth Meaning Hint:

• The word in the OO part is the correct answer.

This suggests that the word we're looking for is represented by "OO."

Fifth Meaning Hint:

• OO is included in the meaning of all words.

Given this hint, it's clear that "OO" is a crucial part of the word we're trying to find.

Putting all these hints together, let's consider words that fit the description:

• The word needs to be versatile and used in common for all meanings.
• It should relate to detective work or reasoning.
• It should also relate to guidance or assistance.
• The word should include "OO."

A word that fits all these criteria is "tool."

• "Tool" can be used in many contexts (e.g., a physical tool, a software tool, a method or approach).
• In detective work, tools like magnifying glasses or logic are used.
• Tools provide guidance or assistance in various tasks.
• The word "tool" contains "OO."

So, my guess for the answer is: tool.

Can you confirm if this is correct?