Thanks. This seems like a solid answer. I still find it unusual that no other modern Romance languages use a word this close to "Alá" as the most frequent word for "praise", but instead something closer to "laud", though I guess "applaud" or "aplaudir" are related to "laud", and these seem to be related to "alabar." Do you suppose long exposure to Arabic could have influenced the development of the words, or at least their frequency, even if they have an attested Latin origin?
The noun alapa “slap in the face” occurs in classical Latin texts. The verbs alapizo and alapor “to slap someone” occur in post-classical texts. (The phrase nil alapari cited in some dictionaries from Plautus, Truc. 928 is an old scholarly conjecture, not accepted by modern editors. There are no references for alapor in classical Latin). The active verb alapo occurs only in a Latin-Greek glossary. (It is quoted in Georges, but not in Lewis/Short). Even if we accept it as a genuine Latin word it is very difficult to fathom the semantic shift from “slap in the face” to “praise”.
alapator “braggart” also occurs only in glossaries. Here too the proposed semantic shift seems difficult.
The word “alabar” comes from the Latin word “alapari” which means “to boast”.
Now the word “alabanza“ most likely comes from the same place although you could say it could come from “الله بنذة” or “Allahu bandha“ which
roughly translates to “God is a blessing” although highly unlikely