Since I've always been interested in Historical Linguistics for this year I got Jeff Kacirk's Forgotten English as a daily calendar. There are six pages every week and each one lists an antique word that is no longer used. Last week one of the words was chirology. It means "The art of conversing with the hands and fingers."
My husband used to be a Sign Language interpreter, I worked at California School for the Deaf for many years, and we raised three Deaf foster children, so I'm obviously interested in conversing with the hands and fingers.
The quotation describing that word is from the late 1800s. At that time, deaf children were forbidden to use Sign Language to communicate in the schools. People believed that would encourage them to speak and read lips. Since most deaf children had lost their hearing due to high fevers and had already been exposed to spoken language, the "Oral Method" might have worked with some of them. Today most of those illnesses are prevented by inoculations or treated with antibiotics. Most childhood deafness is either hereditary, or caused by prenatal damage, sometimes from drug use.
And all culturally Deaf people resent the oral method, which is not used anymore.
And, in the past, the science of Linguistics defined language as written or spoken communication, so Sign Language wasn't considered a language. But that has changed, and today lots of schools and colleges teach it. Lots of people who aren't from Deaf families know at least some Sign Language.
Even though almost nobody would use that antique word to describe it, chirology is accepted and available.