Definition of "Tack" :

noun: sailing a zigzag course

noun: (nautical) the act of changing tack

noun: (nautical) a line (rope or chain) that regulates the angle at which a sail is set in relation to the wind

noun: gear for a horse

noun: a short nail with a sharp point and a large head

noun: the heading or position of a vessel relative to the trim of its sails

verb: reverse (a direction, attitude, or course of action)

verb: fix to; attach

verb: sew together loosely, with large stitches

verb: fasten with tacks

"Tack the notice on the board."

verb: create by putting components or members together

"He tacked together some verses."

verb: turn into the wind

"The sailors decided to tack the boat."