# What is a 9th K-word™?

This puzzle is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles.

I also want to thank a math teacher who shared this riddle when I was in a high school. This riddle is a variation.

For each number from 1 to 9, there exist corresponding K-words™. Here are examples and non-examples:

$$\begin{array}{l|l|l} & \text{K-words™} & \text{Not K-words™} \\ \hline \text{1st} & \text{Japan} & \text{Korea} \\ \text{2nd} & \text{Yttrium} & \text{Scandium} \\ \text{3rd} & \text{Uncle} & \text{Father} \\ \text{4th} & \text{Deception} & \text{Violence} \\ \text{5th} & \text{Duck} & \text{Chicken} \\ \text{6th} & \text{Army} & \text{Navy} \\ \text{7th} & \text{Blackboard} & \text{Chalk} \\ \text{8th} & \text{Arm} & \text{Leg} \end{array}$$

The objective is to give an example of a 9th K-word™.

For anyone who need it, here is a CSV version:

1st Japan      Korea
2nd Yttrium    Scandium
3rd Uncle      Father
4th Deception  Violence
5th Duck       Chicken
6th Army       Navy
7th Blackboard Chalk
8th Arm        Leg


(Though, you don't need a CSV version. A dictionary suffices.)

Subtle Hint:

Other examples and non-examples of K-words™:


K-words       Not K-words
1st Solar eclipse Lunar eclipse
2nd Tooth         Tongue
3rd Samsung       Apple
4th Human         Alien
5th Error         Success
6th Carnivore     Herbivore
7th Chile         Argentina
8th Octagon       Circle


Moderate Hint:

Decisive Hint:

One of the non-examples is a crucial clue.

• Are the listed ones the only existing k-words ? Commented Feb 14, 2020 at 13:12
• @melfnt No, those are just examples. Commented Feb 14, 2020 at 14:26
• Are the listed on the right one, not K-words at all? Or they are K-words but not on the correct number? Commented Feb 14, 2020 at 14:36
• For the record, a CSV (“Comma Separated Values”) version would, er, generally contain commas :)
– Rubio
Commented Feb 14, 2020 at 16:07
• @athin They are not K-words at all, and don't assign to a number. Commented Feb 14, 2020 at 21:27

The rule of K-words™ is:

When we translate them into Korean, their first letter means a digit.

Examples:

If you want to copy & paste Korean words:

일본, 한국
일식, 월식
이트륨, 스칸듐
이, 혀
삼촌, 아버지
삼성, 애플
사기, 폭력
사람, 외계인
오리, 닭
오류, 성공
육군, 해군
육식, 초식
칠판, 분필
칠레, 아르헨티나
팔, 다리
팔각형, 원

Examples of 9th K-words™:

Sphere(구), Google(구글), Cloud(구름), and infinitely more.

Some note:

An English word can be translated into many Koreans words, so I chose the words carefully to fit them in the rule. For example, I didn't translated Army to 군대 or Alien to 이방인. Especially, I didn't translated Apple to 사과 because I treated it as a proper name.