mum

The word 'mum' is a classic example of a nursery word, formed by the simple, reduplicative sounds made by infants. It originates from the natural, early vocalization 'ma' or 'mama', a pattern found across many unrelated languages due to the ease of forming bilabial nasal sounds for a baby. This universal tendency led to its adoption into Middle English from the earlier 'mome'. Over centuries, 'mum' became the standard, affectionate term for 'mother' in British English, retaining its intimate and informal character primarily within family contexts.

The word is a simplex, reduplicative nursery word.