Logical (8)
'logical' is the definition.
(associated in meaning)
This is all the clue.
(Other definitions for rational that I've seen before include "Based on logic or reasoning" , "Not absurd" , "Logical, reasoned" , "Thinking logically" , "Logical; sensible" .)
'logical' is the definition.
(I know that logical can be written as coherent)
This is all the clue.
(Other definitions for coherent that I've seen before include "Sticking together" , "Not rambling in speech or reason" , "Articulate" , "Intelligible and lucid" , "Meaningful" .)
'logical' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for valid that I've seen before include "Effective" , "still in force" , "Sound, well-based" , "Legally acceptable, unexpired" , "Officially acceptable" .)
'logical' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sane that I've seen before include "Mentally sound" , "Right-minded" , "Sound in mind" , "Healthy in mind" , "Rational" .)
'logical' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for reasonable that I've seen before include "Sound" , "description of rationality" , "Fair, rational" , "Not excessive or extreme" , "Fair - inexpensive" .)