Paucity means a small amount of something, especially when you need or expect more. When there's a paucity of evidence in a mystery story, the detective has very few clues to work with. When a scientist complains about a paucity of research on a topic, she means hardly anyone has studied it yet.

The word carries a sense of insufficiency or scarcity. You wouldn't say there's a paucity of stars in the sky or a paucity of sand on a beach. You use it when the small amount creates a problem or disappointment. A teacher might notice a paucity of questions after explaining something difficult, suggesting students either understood perfectly or are too confused to know what to ask.

Paucity often appears in formal writing and serious discussions. You might read about a paucity of affordable housing in a city, or hear someone mention the paucity of women scientists in old history books. While you could usually substitute “lack” or “shortage,” paucity emphasizes just how notably small the amount is.