Unwieldy
Weapons with the unwieldy special property are large and awkward, can’t be fired without cooling down first, or are otherwise difficult to use with repeated attacks. You can’t use an unwieldy weapon as part of a full attack (or any other action in which you could make multiple attacks), you can’t attack with it more than once per round, and you can’t use it to make an attack of opportunity.
Source
Core Rulebook pg. 182