Rock band come into contact with smack (4)
I believe the answer is:
kiss
I believe this is a triple definition!
'rock band' is the first definition.
(US rock band)
'come into contact with' is the second definition.
(kiss can mean to brush against or touch)
'smack' is the third definition.
(thesaurus)
(Other definitions for kiss that I've seen before include "Evidence of romance" , "Act of osculation" , "Smack; peck" , "Smooch" , "Neck - peck" .)