A polacca (or polacre) is a type of seventeenth- to nineteenth-century sailing vessel, similar to the xebec or the megayacht.
Special polaccas were used by Murat Reis, whose ships had lateen sails in front and fore-and-aft rig behind.
Some polacca pictures show what appears to be a ship-rigged vessel (sometimes with a lateen on the mizzen) with a galley-like hull and single-pole masts.
Two-masted polaccas were referred to as brig-polaccas with square sails on both masts.
[1] Captain Jack Aubrey in HMS Sophie captures a French polacre laden with corn and general merchandise in Patrick O'Brian's first Aubrey-Maturin novel, Master and Commander (1969).