"ConcreteCowboy" refers to someone who portrays themselves as a countryman or someone from a rural area but, in fact, lives in an urban/suburban environment often with city luxuries.
"Look at him with his hat and boots, I bet he's a Concrete Cowboy"
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).