Definitions of gap:

• noun:   a narrow opening
• noun:   a conspicuous disparity or difference as between two figures

  Example: "Gap between income and outgo"

• noun:   a pass between mountain peaks
• noun:   an open or empty space in or between things

  Example: "The explosion made a gap in the wall"

• noun:   an act of delaying or interrupting the continuity
• verb:   make an opening or gap in