transom

noun

1. a window above a door that is usually hinged to a horizontal crosspiece over the door

   noun.artifact

   Synonyms fanlight transom window

   Source: WordNet 3.0

2. a horizontal crosspiece across a window or separating a door from a window over it

   noun.artifact

   Synonyms traverse

   Source: WordNet 3.0

3. A horizontal crossbar in a window, over a door, or between a door and a window above it. <i>Transom</i> is the horizontal, as <i>mullion</i> is the vertical, bar across an opening. See <i>Illust.</i> of <u>Mullion</u>.

   noun

   Source: webster1913