Mezzanine, e.g. is a term used to describe a low-ceilinged floor between two main floors of a building. It is often used as an intermediate floor in a large building, such as a shopping mall or office building. The crossword solution for this term is TIER, which is a synonym for level or storey. A mezzanine is typically the third floor of a building, and is usually lower than the other floors. It is often used for storage, or as an extra space for activities such as meetings or conferences.