lacuna

noun6

1. •
   A small blank space; a gap or vacancy; a hiatus.

   • "Our young friend makes up for many obvious mental lacunae by some measure of primitive common sense," remarked Challenger. — 1912
2. •
   An absent part, especially in a book or other piece of writing, often referring to an ancient manuscript or similar.

   • Long lacunae in this inscription make interpretation difficult.
3. •
   A language gap, which occurs when there is no direct translation in the target language for a lexical term found in the source language.
4. •
   (figurative) Any gap, break, hole, or lack in a set of things; something missing.

   • For Beatrice Nutter, there will always be conspicuous lacunae in our mutual understanding, but after almost 30 years here, the anomalies now delight rather than confound her. — 2008
5. •
   A small opening; a small pit or depression, especially in bone.
6. •
   A space visible between cells, allowing free passage of light.