They spread out in all directions (5)
I believe the answer is:
radii
This could be a double definition.
'they' is the first definition.
Both the definition and answer are plural nouns.
Maybe they are linked in a way I don't understand?
'spread out in all directions' is the second definition.
The definition and answer can be both locations as well as being plural nouns.
Perhaps you can see a link between them that I don't see?
Can you help me to learn more?
(Other definitions for radii that I've seen before include "Lines between the center and circumference of a circle" , "Forearm bones: spokes" , "They meet in the middle of a circle" , "Centre-circumference lines" , "Bones of the human forearm" .)