FromGallo- +‎Romance.

Gallo-Romance

1. Alanguage family, comprisingRomance languages spoken inFrance, northernItaly and northernSpain. SpecificallyWalloon,Picard,Norman,French,Franco-Provençal, although broader definitions includeOccitano-Romance,Rhaeto-Romance (Romansch,Ladin,Friulian) and/orGallo-Italic (e.g.Lombard) languages
   • Georg Bossong,Classifications, in:2016, Adam Ledgeway, Martin Maiden (eds.),The Oxford Guide to the Romance Languages (Oxford Guides to the World's Languages), p. 63ff., here p. 66:

     This contact zone is characterized by numerous transitions and continuities. Gascon and Catalan form a transition between Ibero- and Gallo-Romance; Francoprovençal functions as a mediator between northern and southern Gallo-Romance; and the three dialect groups of Raeto-Romance constitute the transitional area between Gallo-Romance and Italo-Romance, especially the northern Italian dialects which are best grouped under the label 'Gallo-Italic'.

2. The ancestor language of the Gallo-Romance languages.
   • 2003, George Melville Bolling, Bernard Bloch,Language‎^[1], volume79, numbers1-2, page360:

     The first written document in Early Old French orGallo-Romance appeared in 842 (Les serments de Strasbourg 'the Strassburg Oaths'), followed by short religious poems ca. 880.

Gallo-Romance (notcomparable)

1. Of or relating to the Gallo-Romance language family or the Gallo-Romance languages.