1. a gap or missing part, as in a manuscript, series, or logical argument; hiatus; unfilled interval.
2. Anatomy: a cavity, space, or depression, especially in a bone, containing cartilage or bone cells.
3. Botany: an air space in the cellular tissue of plants.
Etymology: from Latin lacuna, “pool, cavity”, from lacus, “lake”.
[Mathiole - Incomplete]