脖子 (bó zi) is the colloquial, everyday term for 'neck' in Mandarin — the part of the body connecting the head to the torso. The first character 脖 (bó) specifically refers to the neck or throat region and appears only in compound words like 脖子 or 脖颈; it is not used alone. The second character 子 (zi) is a common noun suffix that adds a diminutive or familiar tone, making the word sound more natural and conversational than the formal term 颈 (jǐng), which appears in medical or literary contexts.

This word is widely used in daily speech across all age groups — for example, when describing physical sensations (e.g., sore neck), clothing (e.g., high-neck sweater), or body language (e.g., craning one’s neck). It’s neutral in register but slightly more informal than 颈部 (jǐng bù), the standard term used in health or anatomy discussions. Children and adults alike use 脖子 freely in casual conversation, instructions, or descriptions of posture and movement.