'barometrical' originates from Modern Latin and Greek via the noun 'barometer', where the prefix 'baro-' came from Greek 'baros' meaning 'weight, pressure' and the element '-meter' came from Greek 'metron' meaning 'measure'.

'barometrical' changed from the noun 'barometer' (from French 'baromètre' and New Latin 'barometrum') and the adjective 'barometric', and eventually became the English adjective 'barometrical'.

Initially, it meant 'of or relating to a barometer', but over time it has been used more broadly to mean 'relating to atmospheric pressure' or measurements of atmospheric pressure.