'pH-responsive' is a compound of 'pH' and 'responsive'. 'pH' originates from the scientific notation introduced by Danish chemist Søren Peder Lauritz Sørensen in 1909 (from Latin elements often cited as 'pondus hydrogenii' or the notion of 'potential/power of hydrogen'), where 'pondus'/'potentia' meant 'weight'/'power' and 'hydrogenii' meant 'of hydrogen'. 'responsive' originates from Latin 'respondēre', where the root 'respond-' meant 'to answer' or 'to react'.

'pH' began as a laboratory notation in the early 20th century and became the standard symbol for the measure of acidity/alkalinity; 'respondēre' passed into Old/Middle English forms (e.g. Middle English 'responden'/'responden') and developed into the modern adjective 'responsive'. Combined usage produced the modern technical compound 'pH-responsive' to describe materials that react to pH.

Initially, 'pH' referred to a notation for hydrogen-related measurement and 'responsive' meant 'answering' or 'reacting'. Over time, 'pH' came to specifically denote the numerical measure of acidity/alkalinity, and 'responsive' broadened to describe materials or systems that change properties under a stimulus; together the compound now means 'changing behavior or properties in response to pH changes'.