Start the letter with something like, 'My dearest acquaintance '.
To further complicate matters, you classify A. as a "dear friend" and B. as merely "an acquaintance".
All my friends and acquaintances bemoaned the fact that they thought it would go under, and the store's manager," Annabelle Siegel, "lives across the street from me, and she's a dear friend".
Family, friends, near and dear ones, and even acquaintances are ever-ready to jump in with a word of advice.
Dear Vice, This is an acquaintance's male-model boyfriend.
Our dear, dear, caring friend.
(Mr. Praed to Vivie, early in their acquaintance: "You know, my dear Miss Warren, I am a born anarchist. I hate authority. It spoils the relations between parent and child").
The New Yorker, July 13 , 1963P. 18 Unsettling note received by a lady of our acquaintance from a nine-year-old nephew: Dear Aunt Grace: I had a wonderful birthday last week.
You must have a wide acquaintance among the astigmatic, haven't you, Freddie, dear?
However, you don't have to read into it; "dear" is as appropriate for a letter to your best friend as it is for a letter to an acquaintance you just met.
