SPACE › an empty space or hole in the middle of something, or between two things: There's quite a big gap between the door and the floor. The sun was shining through a gap in the curtains.
DIFFERENCE › a difference between two groups of people, two situations, etc: an age gap This course bridges the gap between school and university.
ABSENT THING › something that is absent and stops something from being complete: There are huge gaps in my memory.
a gap in the market › an opportunity for a product or service that does not already exist
TIME › a period of time when nothing happens, or when you are doing something different from usual: I decided to go back to teaching after a gap of 10 years. → See also the generation gap