Intransitive verb. To win in a fight without contest. Derived from (rare) to send the opponent on the run and deliver a parting blow with one's foot at the decisive conclusion.
Adjective. The ability to win in a fight or argument without contest.
Noun. By extension, anything that would rock hard enough to win in a fight or as the subject of an argument.
1)My martial arts instructor kicked my ass yesterday.
2)A strong military is kick ass. A country that bargains with or runs from terrorists is not kick ass.
3)A man in uniform is kick ass. Terrorists are not kick ass.
Intransitive verb. 1)The specific ability to perform adeptly a style of rock music which includes guitars, drums, and a blues influence. 2)To surpass all contenders in excellence, ability, or fame. 3) To render all viewers speechless at one's excellence, ability, or fame.
Music. "The vintage vinyl of Bad Company that my dad gave me rocks hard."
Excellence. "Congratulations on that summa cum laude! You really rock hard, Michelle!"
Ability. "Our band really rocked hard last night, didn't it?"
Fame. "The Beatles rocked hard."