accord: [12] In its original source, Vulgar Latin *accordāre, accord meant literally ‘heart-toheart’ (from Latin ad ‘to’ and cord-, the stem of cor ‘heart’). It passed into Old French as acorder, and was borrowed comparatively early into English, turning up in the Anglo-Saxon Chronicle in 1123. Its general sense of ‘being in agreement’ has been narrowed down in English and other languages to the notion of ‘being in harmony musically’, and either Italian accordare or French accorder provided the basis for German akkordion (from which English got accordion), the musical instrument invented by Buschmann in Berlin in 1822. => cordial[accord etymology, accord origin, 英语词源]