Easy to understand (4-8)
There are a few possibilities for this:
user-friendly
'easy to understand' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for clear that I've seen before include "Leap over" , "Obvious; jump over" , "Transparent - free of obstruction" , "Get net" , "Unimpeded" .)
'easy to understand' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lucid that I've seen before include "Rational, clear" , "Clear, intelligible" , "Clear and comprehensible" , "Easily understood; sane" , "unlike 5 [OPAQUE]" .)
'easy to understand' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for user-friendly that I've seen before include "Easily picked up" , "Easy to operate" , "Easy to understand or manipulate" .)