Gaelic is a Noun.It’s a Celtic language spoken in parts of Ireland and Western Scotland and even a part of Canada..It has three variants,Irish,Scottish and Manx…It was on the verge of fading out but there has been a revival of sorts and the Scotland Government is keen to support it’s existence….Barely 100000 people have some ability to speak this language…..As an adjective,Gaelic referes to ‘pertaining to the Gaels’
Gallic is an adjective referring to the French or France…However it also could refer to Gaul,a region in Europe that is traced to being largely a part of Modern France.It also could refer to a Gaulic Celtic Language spoken in Gaul before the Roman conquest
Remember Asterix the Gaul ! ..Asterix and Obelix feature in the hilarious Comic Series that pits their Village in Gaul against the Roman Might of Caesar…no matter how hard the Romans try,these shrewd villagers beat them at their own game