Brian D. Stubbs addresses the use of "adieu" in Jacob 7:27; argues it is a French word that was adopted into English.
Brian D. Stubbs, Changes in Languages from Nephi to Now, 2nd edition (N.P.: Brian D. Stubbs, 2020), 21
critics claim Joseph’s use of French ‘adieu’ (Jacob 7:27) shows a charlatan’s effort to get fancy with a French term in an English translation. What they fail to realize is that half of English is French. In 1066 the Norman French conquered and ruled England, influencing English for centuries. We adopted more French into English than we retained of Old English. Modern English kept merely 15% of its Old English vocabulary. French and Latin loans replaced 85% of Old English. Most astonishing is the ignorance of the critics in not checking to discover that adieu IS English! It is from Middle English adieu, which is from Old French adieu, and so has been part of the English language for several centuries, following the same route as thousands of other French words into English. In other words, adieu has been English as long as all the other terms in bold. In this paragraph the French loans are bolded (26), words from Old English are underlined (30), and Latin and other loans are italicized (13), while articles, prepositions, and proper nouns are not marked.