noun, na-adjective
staunch devotion to one's master; single-hearted loyalty
A yojijukugo describing unwavering, wholehearted loyalty to a lord or master, often with a classical or literary flavor.
彼は忠義一徹の武士として知られていた。
He was known as a samurai of staunch devotion to his lord.
その家臣の忠義一徹な態度に主君は深く感じ入った。
The lord was deeply moved by his retainer's single-hearted loyalty.
A yojijukugo combining 忠義 (loyalty) and 一徹 (single-minded, stubborn). The exact historical origin is uncertain, but it follows the pattern of classical four-character compounds expressing moral ideals.