the entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close; "he stuck his head in the doorway"
a piece of land prepared for playing a game; "the home crowd cheered when Princeton took the field"
the circumstances under which competition occurs; "the government's objective is to insure a genuinely level playing field for American industry and commerce in Europe"
discovered or determined by scientific observation; "variation in the ascertained flux depends on a number of factors"; "the discovered behavior norms"; "discovered differences in achievement"; "no explanation for the observed phenomena"
lengthen in time; cause to be or last longer; "We prolonged our stay"; "She extended her visit by another day"; "The meeting was drawn out until midnight"
lengthen or extend in duration or space; "We sustained the diplomatic negotiations as long as possible"; "prolong the treatment of the patient"; "keep up the good work"