Loyalty to Duty or Master in Chinese / Japanese...

忠 is the simplest way to write the word loyalty in Chinese and Japanese.

A single character like this leaves the meaning open. But alone, a Chinese or Japanese person would think of loyalty to duty or loyalty to one's master (in ancient times). I suppose that it could be loyalty to your boss or company in this day in age.

忠 can also mean fidelity or faithfulness.

This can also be romanized as “chung.”

盡忠報國 is a proverb that is the tattoo worn on the back of Yue Fei, a famous Chinese warrior who lived until 1142 A.D.

The tattoo can be translated as “Serve the country with the utmost loyalty.” More literally, it means “[The] Ultimate Loyalty [is too] Duty [of] Country.”

Legend has it that this tattoo once saved his life when he was accused of treason.

The first two characters have come to create a word that means “serve the country faithfully” or “die for the country.” Note: It's more a willingness to die for one's country than the actual act of dying.

The last two characters have come to mean “Dedicate oneself to the service of one's country.”

Both of these words are probably only in the Chinese lexicon because of this famous tattoo.

If you break it down, character-by-character, here is what you get:
1. To the utmost, to the limit of something, the ultimate.
2. Loyalty or duty (a sense of duty to one's master, lord, country, or job).
3. Report, recompense, give back to (in this case, you are giving yourself to your country as payback).
4. Country, state, nation, kingdom.

More about the famous warrior and army general, Yue Fei