‘光脖子’ literally means 'bare neck' — a colloquial noun describing the state of having one’s neck fully exposed, typically because no shirt, collar, or upper garment is worn. The character 光 (guāng) here functions as an adjective meaning 'bare' or 'uncovered', not 'light'; 脖 (bó) means 'neck'; and 子 (zi) is a common nominal suffix that turns the phrase into a concrete, informal noun. It emphasizes visual exposure rather than temperature or intention — for example, someone might be described as ‘光脖子’ even indoors if they’re wearing only a sleeveless top or no top at all.

This term is frequently used in everyday spoken Mandarin, especially when commenting on dress, weather-appropriateness, or child behavior (e.g., toddlers running around without shirts). It carries a mild, slightly affectionate or teasing tone — not clinical or judgmental — and rarely appears in formal writing. While it can apply to animals (e.g., a bare-necked chicken), its primary usage is human-centered and situational, tied to clothing choices and daily life contexts like home, play, or summer outings.