Weighty describes something that carries significant importance or seriousness. When your teacher announces she needs to discuss a weighty matter with the class, she means something serious and consequential that will affect the whole class. A decision about which high school to attend is weighty because it affects your future in meaningful ways.

The word also means heavy in physical mass, and you'll still hear it used that way: a weighty tome is a thick, heavy book. But more often, weighty describes things that feel heavy because of their importance or difficulty. A judge faces weighty decisions that affect people's lives. A scientist working on artificial intelligence deals with weighty questions about the implications of the technology.

Weighty suggests that something deserves careful, thoughtful attention. A weighty responsibility requires your best judgment and sustained effort, like being trusted to care for a younger sibling or manage an important project. When a friend shares something weighty with you, like worries about their family, they're trusting you with something that matters deeply to them. The word helps us distinguish between everyday concerns and truly significant ones that deserve our full attention and wisdom.