'outspokenness' originates from English, specifically the combination of 'out-' + 'spoken' + '-ness', where 'out-' meant 'out' or 'beyond', 'speak' (past participle 'spoken') meant 'to utter', and '-ness' is a noun-forming suffix indicating a state or quality.

'outspoken' was formed by combining 'out' with the past participle 'spoken' (from Old English 'sprecan'/'sprecan' → Middle English 'spreken'/'spoken'), and later the suffix '-ness' was added to produce the abstract noun 'outspokenness'.

Initially the components referred simply to 'uttered outwardly' or 'spoken out', but over time 'outspoken' came to mean 'frank or candid in speech', and 'outspokenness' evolved to denote the quality of such frankness.