'barometrically' originates from English adjective 'barometric', ultimately from Modern Latin 'barometrum', where 'baro-' meant 'weight' and 'metron' meant 'measure'.

'barometrically' changed from English adjective 'barometric', which was formed from the noun 'barometer' (17th century) derived from Modern Latin 'barometrum' and ultimately from Greek 'baros' + 'metron', and eventually became the English adverb 'barometrically'.

Initially, the roots referred to 'measuring weight', but over time the sense shifted to 'measuring or relating to atmospheric pressure', which is the current meaning.