'two-line' originates from English, specifically the words 'two' and 'line'; 'two' ultimately comes from Old English 'twa' meaning 'two', and 'line' comes from Latin 'linea' meaning 'linen thread, line'.

'two' changed from Old English 'twa' to the modern English 'two'; 'line' changed from Latin 'linea' to Old French 'ligne' and Middle English 'line', eventually becoming modern English 'line'. The compound 'two-line' is a straightforward modern English combination of these elements.

Initially the components meant 'two' and 'a thread/mark (line)'; over time the compound came to be used to describe something composed of two lines (written or printed).