‘一顿’ (yì dùn) is a measure word used specifically for meals — literally ‘one meal’. It combines the numeral ‘一’ (yī, ‘one’) and the measure word ‘顿’ (dùn), which by itself means ‘a sitting’ or ‘a serving’ of food. Unlike general measure words like ‘个’, ‘顿’ applies exclusively to meals: breakfast, lunch, dinner, or even an informal snack that constitutes a full eating occasion. It conveys completeness — one full, self-contained eating event.

This term appears frequently in daily conversation, especially when discussing frequency (e.g., ‘一天吃三顿’ — ‘eat three meals a day’), duration (‘吃了顿好的’ — ‘had a good meal’), or emotional context (‘气得吃不下一顿饭’ — ‘was too angry to eat a single meal’). It’s neutral in register and used across all age groups and settings — from casual chats to written reports about dietary habits.