single-minded loyalty; steadfast devotion to one's master
Describes unwavering, wholehearted loyalty, typically in a feudal or hierarchical context. Often used with に as an adverbial phrase.
He served his lord with single-minded loyalty.
He was known as a retainer of unwavering devotion.
忠義 is the general concept of loyalty and devotion, while 忠義一途 emphasizes the single-minded, wholehearted nature of that loyalty.
一途 alone means 'single-minded' or 'earnest', but 忠義一途 specifically applies this intensity to loyalty toward a master.
Compound of 忠義 (loyalty) and 一途 (single-minded, wholehearted). The exact historical derivation is uncertain, but the combination straightforwardly conveys intense, undivided loyalty.