To bring separate parts, groups, or things together so they become one — or, said the other way round, for them to come together into one. It works both ways in English: you can unify something ("the king unified the country"), and things can unify by themselves ("the small parties unified against the new law"), though the first is far more common. The big political use is the one you meet in history class: unify a country, unify a divided nation. But the word has spread widely into technology and business. Companies unify their systems so all the data sits in one place; a designer unifies a website so every page looks like it belongs to the same family. In that use, unify means getting rid of the messy differences between pieces that should match. There is also a softer, human use: a leader who unifies people, a cause that unifies a community. Here it does not mean melting people into one — it means giving them one purpose so they stop pulling apart. That is worth holding on to, because unify does not always mean things physically join; sometimes it just means they now point the same direction.