window has 1 distinct synonym spread across 1 of its 8 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a framework of wood or metal that contains a glass windowpane and is built into a wall or roof to admit light or air
a transparent opening in a vehicle that allow vision out of the sides or back; usually is capable of being opened
a transparent panel (as of an envelope) inserted in an otherwise opaque material
an opening that resembles a window in appearance or function
“he could see them through a window in the trees”
the time period that is considered best for starting or finishing something
“the expanded window will give us time to catch the thieves”
an opening in a wall or screen that admits light and air and through which customers can be served
“he stuck his head in the window”
(computer science) a rectangular part of a computer screen that contains a display different from the rest of the screen
Synonyms, antonyms and the broader and narrower relations for window come from Princeton University’s WordNet. Full sources and licences.