Of sound mind (4)
'of sound mind' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for sane that I've seen before include "Compos mentis" , "In full possession of mental faculties" , "Sound in mind" , "Mentally healthy" , "Identical" .)
'of sound mind' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for lung that I've seen before include "Organ used for breathing" , "breather" , "Of sound mind" , "Breathing apparatus" , "Air bag?" .)