'same-numbered' is a modern English compound formed from 'same' (Old English 'same', meaning 'identical' or 'unchanged') + 'numbered' (from 'number' + past-participial suffix '-ed').

'number' originates from Latin 'numerus', passed into Old French as 'nombre' and into Middle English as 'nombre/number'; the adjectival past-participial form 'numbered' arose by adding the English suffix '-ed'. 'same' comes from Old English 'sama'/'sam'. These elements combined in Modern English to form the compound 'same-numbered'.

Each element has retained its core sense: 'same' meaning 'identical' and 'numbered' relating to number; together they mean 'having the identical number' and this usage is a straightforward modern compound rather than a word with a large historical shift in meaning.