(nautical) The act of tacking, turning into the wind so the sail moves to the opposite side. / (idiomatic) A reversal of an opinion.

(automotive) A mechanism which changes gears in a vehicle.

plural of sea change

That contributes to climate change

To make patterned sound sequences on bells, starting and ending on the same tone. / To run through all possible variations. / (slang, UK, 19th century and earlier) To pass counterfeit money.

The changing of clocks one hour forward or backward, in line with daylight saving time.

plural of hour change

An instruction to a taxi driver, waiter etc. to keep the change from the amount handed over as a tip.

An impermeable pad that babies are placed on while changing their diapers.

(idiomatic, dated, euphemistic) Menopause.