S: (n) opening, gap (an open or empty space in or between things) "there was a small opening between the trees"; "the explosion made a gap in the wall"
S: (n) space (an empty area (usually bounded in some way between things)) "the architect left space in front of the building"; "they stopped at an open space in the jungle"; "the space between his teeth"
S: (n) entity (that which is perceived or known or inferred to have its own distinct existence (living or nonliving))
S: (n) window (the time period that is considered best for starting or finishing something) "the expanded window will give us time to catch the thieves"; "they had a window of less than an hour when an attack would have succeeded"