Definition from Wiktionary, the free dictionary
- (transitive) To beat, smack or slap a person's buttocks, with the bare hand or other object, as punishment, gesture or form of sexual interaction.
- (transitive) To soundly defeat, to trounce.
- (intransitive) To move rapidly.
- The ship was really spanking along.
Derived terms 
To smack or slap a person's buttocks, with the bare hand or other object.
See also 
spank (plural spanks)
- An instance of spanking, separately or part of a multiple blows-beating; a smack, swat or slap.
- A slapping sound, as produced by spanking.
An instance of spanking; a smack or slap