To miniaturize something is to make it in a very small size, or to design it again so the same job fits into something much smaller. You hear this most with machines and electronics: a radio that once filled a box is miniaturized until it sits in a pocket; a camera that needed a bag becomes a chip. Engineers miniaturize parts, circuits, sensors. It is a fairly technical verb — a news report, a science teacher, or a product team might use it. In ordinary talk a child more often just says “make it smaller”. The useful extra meaning is “pack the same work into less space”, not “make a cute small copy for the shelf”. A small copy of a building is a miniature (that is a noun). To miniaturize is the verb for shrinking the real thing, especially technology. You can miniaturize a device or a system. You would not usually say you miniaturized a sandwich or a story. American spelling is miniaturize; British books often use miniaturise. Same word.

微型化、小型化（多指把機器、零件做得更小；不是做迷你模型）