'lignify' originates from Latin, specifically the word 'lignum', where 'lignum' meant 'wood', and from the Latin suffix '-ficare' (via Old French/Medieval Latin) meaning 'to make'.

'lignify' changed from Late Latin/Medieval Latin 'lignificare' (from 'lignum' + 'ficare') into Modern Latin/English 'lignify' and its past participle form 'lignified'.

Initially it meant 'to make into wood' (to render woody), but over time it also developed a figurative sense of 'to make rigid or hardened' (e.g., style or institution).