'diplomatically-expressed' originates from the English adverb 'diplomatically' (from Greek 'diplōma' via Latin and French), where 'diplōma' meant 'folded paper; official document,' and from the verb 'express' (Latin 'exprimere'), where 'ex-' meant 'out' and 'primere' meant 'to press.'

'Diplomatic' developed in English from French 'diplomatique' and Medieval Latin 'diplomaticus' (linked to documents of state), yielding the adverb 'diplomatically.' In parallel, Latin 'exprimere' became Old French 'espresser/exprimer,' then Middle English 'expressen,' leading to modern English 'express' and its past participle 'expressed.' These combined as the compound modifier 'diplomatically-expressed.'

Initially, 'diplomatic' related to official documents and later to the practice of managing international relations tactfully; 'express' originally meant 'to press out,' then 'to state or convey.' Together, the compound came to mean 'phrased with tact and sensitivity.'