'preprandially' originates from Latin, specifically the prefix 'prae-' and the noun 'prandium', where 'prae-' meant 'before' and 'prandium' meant 'meal'.

'preprandial' appeared via Medieval Latin 'praeprandialis' (formed from 'prae-' + 'prandium') and passed into modern English as 'preprandial'; the adverbial form 'preprandially' is formed by adding the English adverbial suffix '-ly'.

Initially it meant 'before a meal' in Late/Medieval Latin contexts, and over time it retained essentially the same specialised meaning in English: 'before eating'.