Horizontal (4)
'horizontal' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for level that I've seen before include "Flush" , "Palindromic storey" , "Even; a plane" , "Flatten" , "Not in front or behind" .)
'horizontal' is the definition.
(similar in meaning)
This is the entire clue.
(Other definitions for flat that I've seen before include "not deep?" , "12 [TWO DIMENSIONAL]" , "like some races" , "Even -- pitched too low" , "Boring - apartment" .)