'prudishness' originates from English, formed by adding the noun suffix '-ness' to the adjective 'prudish'. 'Prudish' itself comes from the noun 'prude' (from French), which referred to a modest or virtuous person.

'prudishness' changed from the English adjective 'prudish' (derived from French 'prude', from earlier forms like Middle French 'prudefemme' meaning a modest woman) and eventually became the modern English noun 'prudishness' through the addition of '-ness'.

Initially it related to being 'prudent' or 'respectably modest', but over time it evolved into its current sense of 'excessive modesty or being easily shocked, especially about sexual matters'.