split level

Short definition from Wiktionary

Adjective

1. 1
   Alternative spelling of split-level.
2. 2
   Of a building: built with rooms on levels separated by stairs of less than a full storey.
3. 3
   Anything else built on two levels.

Noun

1. 1
   Alternative spelling of split-level.
2. 2
   A single level of a split-level house.
3. 3
   A building (especially a house) of this kind.