Lewis Short
mappa (noun F) : Punic, Quint. 1, 5, 57
* A napkin, table-napkin; a towel.
* Lit.: Varius mappa compescere risum Vix poterat,Hor. S. 2, 8, 63: laticlavia,Petr. 32; Mart. 4, 46, 17: rubra detergere vulnera mappa,Juv. 5, 27.
* Transf., a cloth with which the signal for starting was given to racers in the circus, a signalcloth: mappam usitatum Circo nomen, Poeni sibi vindicant,Quint. 1, 5, 57: mappa cretata,Mart. 12, 29, 9: Megalesiacae spectacula mappae,Juv. 11, 191: aliquo liberto mittente mappam, unde magistratus solent,Suet. Ner. 22.
Charlton T. Lewis, Charles Short, A Latin Dictionary