From The Collaborative International Dictionary of English v.0.48:
Fess \Fess\, Fesse \Fesse\, n. [OF. fesse, faisse, F. fasce, fr.
L. fascia band. See Fascia.] (Her.)
A band drawn horizontally across the center of an escutcheon,
and containing in breadth the third part of it; one of the
nine honorable ordinaries.
[1913 Webster]
Fess point (Her.), the exact center of the escutcheon. See
Escutcheon.
[1913 Webster]