"speaking acquaintance" is a correct and usable phrase in written English.
It is used to refer to a person that one knows only from speaking with them, but doesn't know much about them. Example: "We are just a speaking acquaintance, but I still enjoy having conversations with him."
So the next time you're speaking to that acquaintance, slip their name in.
Until he began to speak, new acquaintances sometimes took him for an idiot, as did the artist William Hogarth, who came to admire him greatly.
According to the international official, who has spoken with acquaintances of Mr. Hemed, the young Yemeni first arrived in Mogadishu about two years ago with a conspicuous amount of money.
The police said that Hancock was speaking with a female acquaintance about baseball and baseball tickets and that the conversation ended abruptly, apparently when the accident occurred.
Through five years, Mr. Cramer pursued DiMaggio's life relentlessly, speaking to people whose acquaintance with him went back more than 70 years.
"It doesn't matter if you're a blonde, even," an acquaintance says, speaking of the hysteria and panic that seem to be spreading through Israeli society, "someone starts screaming that you're a terrorist and you're done".
I was speaking to a Chinese acquaintance the other day who has spent much of her adult life in San Francisco, is married to an American, yet finds herself these days missing the China that once was and is fast disappearing.
Former friends and acquaintances, most speaking on condition of anonymity, challenged elements of Cole's account to the Guardian and called him pathologically duplicitous, alleging he padded his film resume on the IMDb database with fictitious entries.
The doctor listened in amazement as his new acquaintance spoke at length of the chemistry experiment he'd just completed.
He spoke with an acquaintance about acquiring the gas cutters and he also sent several coded messages to contacts in Pakistan from April 2002 to March 2003 to update them on the status of the project.
