'pithiness' originates from English, specifically formed from the adjective 'pithy' plus the suffix '-ness', where 'pithy' derived from the noun 'pith' meaning 'marrow' or 'essence'.

'pith' comes from Old English 'piþ(a)' (written with the letter þ, thorn) meaning 'marrow, core, essence', which passed into Middle English; the adjective 'pithy' arose in Early Modern English to mean 'full of pith/substance', and 'pithiness' was later formed by adding the noun-forming suffix '-ness' to 'pithy'.

Initially it related to having 'pith' or substance (literally 'full of core/essence'), but over time it evolved to emphasize concise, forceful expression—'concise and meaningful' as the modern sense.