a. 1. Moving with a quick, lively pace, or capable of so doing; dashing. [ 1913 Webster ]
Four spanking grays ready harnessed. G. Colman, the Younger. [ 1913 Webster ]
2. Large; considerable. [ Colloq. ] [ 1913 Webster ]
3. Very; extremely; -- used especially in the phrase spanking new or brand spanking new, meaning completely new and unused. [ informal ] [ PJC ]
(Naut.), a strong breeze. [ 1913 Webster ]