It's fway-lawn. Usual the surname is Ó Faoláin, Ó meaning from and then Faoláin has an extra 'i' as it's the possessive form of Faolán. As an aside the girls surname is Ní Fhaoláin (nee ay-lawn) and Mrs is Bean Uí Fhaoláin (Ban ee ay-lawn).
On it's own, as a noun it means seagull. As a surname it is anglcised as the surnames Whelan/Phelan, which is probably where some of the pronounciations have come from. As far as I can remember I was told it's meaning is sly wolf, but I wouldn't take that as gospel. I don't normally know so much about names, but it's my maiden surname!!