English has very few words left from the Ancient British. I am wondering if the language of the Gauls suffered much the same fate, or whether there are significantly more Celtic substrate words remaining in French than in English. My suspicion is yes, both because the Latin antecedents of French were more similar to Celtic than the German (of the Angles) was; and because the Angles mostly displaced the Britons, whereas the Franks more became the ruling elite of the Gauls.
See en.wiktionary.org/wiki/…. Mostly placenames, or words like branch or iron, that were borrowed into Latin or early continental Germanic, and simply inherited by many languages. The actual number of Celtic placenames across Europe is in the tens of thousands or more.– Adam BittlingmayerNov 16, 2022 at 9:26
Minor thing, but the Angles didn't speak German per se.– wjandreaNov 16, 2022 at 20:11
Not really, modern French has preserved only very few Celtic words not counting geographical names. The loss of Celtic words already happened in Gallo-Romance, the Frankish takeover had indeed little effect on that.
When you are looking for a Romance language with a larger Celtic substrate component, you should look at Romansh, Ladinian, and Friulian (see the question Which Romance Language retains the most words from Celtic? and its answers)