The Collaborative International Dictionary of English v.0.48:
Flawn \Flawn\ (fl[add]n), n. [OF. flaon, F. flan, LL. flado, fr. OHG. flado, G. fladen, a sort of pancake; cf. Gr. ? broad. See Place.] A sort of flat custard or pie. [Obs.] --Tusser. [1913 Webster]