1. a couch or single bed with a mattress and frame concealed beneath, which, when pulled all the way out, lift up to the level of the upper cushion or mattress and lock into place to form a double bed.
  2. a high-rise bicycle.
  3. high-rise(def 4).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018