'confidentially-declared' originates from Latin roots: 'confidentially' traces to Latin 'confidere' ('to trust') via French and English 'confidential', and 'declared' comes from Latin 'declarare' ('to make clear, proclaim') via Old French and English 'declare'.

'confidentially-declared' formed in modern English as a hyphenated compound modifier: English 'confidentially' (from Middle French/Latin routes) combined with English past participle 'declared' (from Old French 'declarer' < Latin 'declarare') and eventually became the modern English compound 'confidentially-declared'.

Initially, the roots meant 'to trust' and 'to make clear/proclaim'; combined, the sense developed into 'declared in confidence', now used to mean 'officially stated but intended to remain private'.