The word 老师 is formed by combining two characters: 老 (lǎo), which literally means "old" but here functions as an honorific prefix denoting respect and experienced status, and 师 (shī), which means "teacher", "master", or "model". The fusion creates a single term where 老 intensifies and venerates the core concept of 师, resulting in a compound noun that specifically means "teacher" with a connotation of respect and seniority, rather than merely an "old teacher".