Coward some regard as tardy (7)
I believe the answer is:
dastard
'coward' is the definition.
(similar in meaning)
'some regard as tardy' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'DASTARD' is hidden in the letters of 'regard as tardy'.
(Other definitions for dastard that I've seen before include "contemptible scaredy-cat" , "Coward" , "Cowardly fellow" , "despicable fellow!" .)