sense of decorum; awareness of common courtesy
Refers to an innate or cultivated sensitivity to proper manners and everyday social courtesies.
He lacks a sense of decorum.
As a working adult, you should acquire at least a basic sense of common courtesy.
礼儀 refers to manners or etiquette themselves, while 礼儀感覚 is the internal sense or awareness of such manners.
マナー is a more common, everyday word for manners, often used in practical contexts; 礼儀感覚 is more formal and emphasizes an inner sensibility.
Compound of 礼儀 (courtesy, manners) and 感覚 (sense, sensation). The exact historical derivation is uncertain, but the word transparently combines these elements.