A clontarf is a feminized liberal male douchebag; a know-it-all phloom who has to have the last word in every conversation; a guy who uses puns, big words, and trivia questions to show everyone how smart he is; a dick weed who always corrects your spelling. Like a black hole, he sucks all other conversation out of the room so that he can only hear himself talk.
See also phloom.
We were laughing our asses off until that clontarf showed up. Fuckin' phloom!
the best area in da whole of ireland, perfetly balanced, evry1 is stuk up ther own whole like in places such as blackrock and other posh areas but its not a big knacker hole like ballymun or finglas, etc.