: to join or add in a slight or hasty manner—usually used with on or onto
… the upbeat ending, tacked on to a book that cries out for a tragic one. Julian Symons
3
a
: to add as a supplement or something extra—usually used with on or onto
tacked fees onto the priceThe Marlins tacked on five runs in the bottom of the eighth … Buster Olney
b
: to add (a rider) to a parliamentary bill
provisions tacked to an appropriation bill
4
: to change the direction of (a sailing ship) when sailing close-hauled by turning the bow to the wind and shifting the sails so as to fall off on the other side at about the same angle as before
Although some believe the word tact is short for tactics in phrases like "change tact" or "try a different tact," the correct word in such contexts is tack.
Tack in "change tack" and "try a different tack" means "a course or method of action especially when sharply divergent from that previously followed.”
Tack developed this meaning from its nautical applications. In sailing, tack can refer to the direction that a ship or boat is sailing in as it moves at an angle to the direction of the wind; or to a change from one direction to another direction; or to the distance traveled while sailing in a particular direction.
Tack developed the "course or method of action" meaning near the end of the 17th century; within 100 or so years, the phrase "change tack" was being used with the figurative meaning it has today.
While there is also a long history of people using tact where tack belongs, the use is widely shunned by usage guides, which means you might want to avoid it.
Verb She tacked a poster on the wall. A message was tacked to the board. We had to tack repeatedly as we sailed toward the harbor.
Word History
Etymology
Verb
Middle English takken, from tak
Noun (1)
Middle English tak fastener, rope tying down the windward corner of a sail, from Middle French (Norman dialect) taque; akin to Middle Dutch tac sharp point