Weyto language
Weyto is a speculative extinct language thought to have been spoken in the Lake Tana region of Ethiopia by the Weyto, a small group of hippopotamus hunters who now speak Amharic. The Weyto language was first mentioned by the Scottish traveler James Bruce, who spoke Amharic. Bruce passed through the area about 1770 and reported that "the Wayto speak a language radically different from any of those in Abyssinia," but was unable to obtain any "certain information" on it, despite prevailing upon the king to send for two Weyto men for him to ask questions, which they would  neither answer nor understand even when threatened with hanging. The next European to report on the Weyto, Eugen Mittwoch, described them as uniformly speaking a dialect of Amharic (Mittwoch 1907). This report was confirmed by Marcel Griaule when he passed through in 1928, although he added that at one point a Weyto sang an unrecorded song "in the dead language of the Wohitos" whose meaning the singer himself did not understand, except for a handful of words for hippopotamus body parts which, he says, had remained in use. This Amharic dialect is described by Marcel Cohen (1939) as featuring a  fair number of words derived from Amharic roots but twisted in sound or meaning in order to confuse outsiders, making it a sort of argot. In addition, the dialect had a small number of Cushitic loanwords not found in standard Amharic, and a large number of Arabic loanwords mainly related to Islam. Of the substantial wordlist collected by Griaule, Cohen only considered six terms to be etymologically obscure: "šəlkərít" "fish-scale", "qəntat" "wing", "čəgəmbit" "mosquito", "annessa" "shoulder", "nkes" "hippopotamus thigh", "wazəməs" "hippopotamus spine." By 1965, the visiting anthropologist Frederick Gamst found "no surviving native words, not even relating to their  hunting and fishing work tasks." (Gamst 1965.) The paucity of the data available has not prevented speculation on the classification of their original language; Cohen suggested that it might have been either an Agaw language or a non-Amharic Semitic language, while Dimmendaal (1989) says it "probably belonged to Cushitic" (as does Agaw), and Gamst (1965) says "...it can be assumed that if the Wäyto did not speak Amharic 200 years ago, their language must have been Agäw..." According to the Ethnologue, Bender "et al." (1976) saw it as Cushitic, while Bender 1983 saw it as either Eastern Sudanic or  Awngi. It thus effectively remains unclassified, largely for lack of data, but possibly related to Agaw.