From demo (to build); properly, an edifice, i.e. (specially) a roof -- housetop.
1. a building, house, (Homer and following).
2. a part of a building, dining-room, hall, (Homer and following).
3. in the Script. equivalent to γααγ house-top, roof (Winer's Grammar, 23): Matthew 24:17; Mark 13:15; Luke 5:19; Luke 17:31. The house-tops of the Orientals were (and still are) level, and were frequented not only for walking but also for meditation and prayer: Acts 10:3; hence, ἐπί δωμάτων, on the house-tops, i. e. in public: Matthew 10:27; Luke 12:3; ἐπί τό δῶμα ... κατ' ὀφθαλμούς παντός Ἰσραήλ, 2 Samuel 16:22.