Antonyms of adj tardy

1 sense of tardy

Sense 1
belated, late, tardy -- (after the expected or usual time; delayed; "a belated birthday card"; "I'm late for the plane"; "the train is late"; "tardy children are sent to the principal"; "always tardy in making dental appointments")

INDIRECT (VIA unpunctual) -> punctual -- (acting or arriving or performed exactly at the time appointed; "she expected guests to be punctual at meals"; "he is not a particularly punctual person"; "punctual payment")

Similarity of adj tardy

1 sense of tardy

Sense 1
belated, late, tardy -- (after the expected or usual time; delayed; "a belated birthday card"; "I'm late for the plane"; "the train is late"; "tardy children are sent to the principal"; "always tardy in making dental appointments")
       => unpunctual (vs. punctual) -- (not punctual; after the appointed time)