To synchronize means to make things happen at the same time or work together in a coordinated way. When swimmers synchronize their movements in a routine, they dive, spin, and surface at exactly the same moments. When you synchronize your watch with your friend's watch, you adjust them so they show the identical time.

You might synchronize your calendar across your phone and computer so changes on one device appear on the other. Musicians synchronize their playing so the orchestra sounds unified rather than chaotic. In a movie, sound technicians synchronize the actors' lip movements with the dialogue so everything matches perfectly.

Sometimes things synchronize naturally, like fireflies that flash in unison or people walking together who unconsciously match their stride. But usually synchronization takes effort and attention. When a marching band synchronizes its steps and music, they practice for hours to achieve that precision.

The opposite would be things happening randomly or out of coordination. If you've ever seen a poorly dubbed movie where the actors' mouths don't match the words, you've seen what happens when synchronization fails. Getting complex systems to work in sync requires careful planning, whether you're coordinating a dance performance, a military operation, or just trying to meet your friends at the same place at the same time.