- (microscopy) A space visible between cells, allowing free passage of light.
- An absent part, especially in a book or other piece of writing, often referring to an ancient manuscript or similar such.
"Long lakunae in this inscription make interpretation difficult."
- A small opening; a small pit or depression; a small blank space; a gap or vacancy; a hiatus.
- (linguistics) A language gap, which occurs when there is no direct translation in the target language for a lexical term found in the source language