To furnish something means to supply or provide what's needed. When you furnish information to your teacher, you give them the facts they asked for. When a witness furnishes evidence in court, they provide proof that helps solve a case.

The word most commonly describes filling a room or building with furniture. When a family furnishes their new apartment, they add beds, tables, chairs, and everything else needed to make the space livable and comfortable. A furnished apartment comes with furniture already in it, so you can move in without bringing your own couch or dining table.

Notice the connection: whether you're furnishing a room with chairs or furnishing a friend with directions, you're providing what's missing or needed. The word suggests completing something, making it ready for use. A scientist might furnish colleagues with research data. A hotel furnishes guests with towels and toiletries. When you furnish someone with an explanation, you're giving them the understanding they need.