Определение middle-distance в Английский Язык Английский Язык словарь
a middle-distance race is neither very short nor very long, for example 800 or 1500 metres
A middle-distance runner is someone who takes part in races of medium length, for example 800 metres. the part of a picture or view that is between the nearest part and the part that is furthest away
If you are looking into the middle distance, you are looking at a place that is neither near nor far away. He stares detachedly into the middle distance, towards nothing in particular