What does the french word alo mean?

The French word "alo" is not a standard French word. It might be a misspelling of:

* Allô: This is the French equivalent of "hello" used to answer the phone.

* A-lot: This is an incorrect spelling of the English phrase "a lot," which means "many."

If you provide more context about where you saw the word "alo," I might be able to give you a more accurate answer.