This is the 9147th most frequent German word.
luftlinie
"Straight line distance" between two points.
The word 'luftlinie' is used here to describe a direct line measurement between two points measured without considering actual travel routes.
Die Entfernung zwischen den beiden Städten beträgt 50 Kilometer luftlinie.
The distance between the two cities is 50 kilometers as the crow flies.
In this sentence, 'luftlinie' refers to a straight distance between two locations, not accounting for geographical or man-made road paths.
Von meinem Haus aus zum See sind es nur zehn Kilometer luftlinie.
From my house to the lake is only ten kilometers as the crow flies.
Here, 'luftlinie' defines the spatial separation in a straight line from one point to another.