Perpetually means constantly, continuously, or seemingly without end. When something happens perpetually, it keeps happening over and over, or never seems to stop.

A student who is perpetually late arrives late again and again, day after day. A machine that runs perpetually operates without stopping. Some people seem perpetually cheerful, always smiling and optimistic no matter what happens. Others might be perpetually curious, constantly asking questions and wanting to learn more.

The word suggests something that goes on indefinitely, though it doesn't necessarily mean forever in the literal sense. When someone says they're perpetually hungry, they probably don't mean they're hungry every single second, but rather that they seem to be hungry much of the time. A messy desk that's perpetually cluttered never quite gets cleaned up and organized.

The related noun is perpetuity, which means the state of lasting forever. Scientists searching for perpetual motion machines tried to create devices that would run forever without any energy input, but the laws of physics make this impossible.