'transliterate' originates from Latin, specifically the word 'translitterare' (attested in Late/Medieval Latin), where 'trans-' meant 'across' and 'littera' meant 'letter'.

'transliterate' developed from Late/Medieval Latin 'translitterare' (to transfer letters) into Modern Latin/English usage and was adopted into English with the sense of converting letters between alphabets.

Initially it meant 'to transfer or copy letters across (scripts)', and over time it has kept that core sense but been specialized to mean systematic conversion of characters between writing systems rather than translation of meaning.