'all\'incirca' originates from Italian, specifically the elements 'a' + 'il' (contracted to 'all\'') and 'circa', where 'a' meant 'to/at' and 'circa' meant 'around'.

'circa' comes from Latin 'circā' (or from the preposition 'circum' in related forms) meaning 'around'; it passed into Medieval Latin as 'circa' and then into Italian as 'circa'. The Italian contraction 'a' + 'il' produced 'all\'' before a vowel, giving the modern Italian phrase 'all\'incirca', which is used to mean 'about/around'.

Initially the root 'circa' meant 'around' in a spatial sense; over time, in phrases like 'all\'incirca' it shifted to the more general sense of 'approximately' or 'about' when indicating quantities or times.