To back and fill Meaning, Definition & Usage

Definitions
  1. to manage the sails of a ship so that the wind strikes them alternately in front and behind, in order to keep the ship in the middle of a river or channel while the current or tide carries the vessel against the wind. Hence: (Fig.) To take opposite positions alternately; to assert and deny. Colloq.
Definitions
  1. . See under Back, v. i.

Webster 1913