'variable' originates from Latin, specifically the word 'variabilis,' where 'vari-' meant 'to change.' 'Temperature' comes from Latin 'temperatura,' meaning 'a mixing in due proportion.'

'Variable' changed from the Old French word 'variable' and eventually became the modern English word 'variable.' 'Temperature' evolved from the Latin 'temperatura' through Old French 'temperature.'

Initially, 'variable' meant 'able to change,' and 'temperature' meant 'a mixing in due proportion.' Over time, 'variable-temperature' evolved to mean a system that can operate at different temperatures.