'fairly-stated' originates from English, formed by combining the adverb 'fairly' (from 'fair' + suffix '-ly', ultimately from Old English 'fæger') and the past participle 'stated' (from the verb 'state', from Old French 'estat', Latin 'status' < 'stare' meaning 'to stand').

'fairly-stated' developed in Modern English as a hyphenated phrasal adjective used before nouns (e.g., 'a fairly-stated account'). The component 'fairly' arose from Old English 'fæger' with the adverbial suffix '-ly', and 'state' entered English via Old French 'estat' from Latin 'status'.

Initially used literally to mean 'stated in a fair manner', and this sense remains the primary meaning in modern usage.