1931 Times Lit. Suppl. 19 Feb. 128/2The Dano-German Münte. 
1880 Encycl. Brit. XIII. 252/2The many feuds between the Irish clans in which the Dano-Irish shared. 
Ibid. ,During the independence of the Dano-Irish kingdom of Dublin. 
1892 J. Y. Sargent Gram. Dano-NorwegianLang. p. vi,I have given..the Syntax of sentences simple and compound, so far as the Dano-Norwegian idiom differs from the English. 
1911 Encycl. Brit. XIX. 818/1The close of 1899 and the beginning of 1900 were occupied by a discussion..as to the adoption of the landsmaal..in place of the rigsmaal or Dano-Norwegian. 
1933 Bloomfield Lang. iv. 59The present-day standard languages are Icelandic, Danish, Dano-Norwegian, Norwegian Landsmaal, and Swedish. [ in Scandinavia] 
Ibid. xxvii. 484The Norwegians modified their standard Danish in the direction of Norwegian speech-forms. This Dano-Norwegian Riksmaal (‘national language’) became the native speech of the educated upper class. 
1961 L. F. Brosnahan Sounds ofLang. ix. 205The Riksmål, which originated in the Dano-Norwegian speech of the educated population of the south-east. 
ORIGIN: from Latin  Danus  Danish -o- 
Dano-
Prefix
- pertaining to Denmark, especially as a political entity
Etymology
Shortened unetymologically from Denmark in compounds- 20th century formation, perhaps echoing terms like Afro-, Indo-, Sino- etc.