Although this question might be a naive thing to ask, I believe that I would get an much detailed answer to this question keeping in mind all my simple questions answered wonderfully by people in the past. I read the wiki page on Tsundere but there's not much, I understand the broad definition where a person has a combative attitude towards a particular protagonist in any anime. What I am looking for, is an all-encompassing criteria/concept of a 'tsundere' and the highlights of their social behavior.
The word tsundere is a portmanteau of the japanese terms tsun-tsun (turning away in disgust) and dere-dere (lovey-dovey feelings).
Typically tsundere characters are characters who aren't honest with themselves about loving another character. They'll often say things like;
"It's not as if it I did that for you, dummy - don't get the wrong idea!"
"It could have been anyone else, it's just because you were there"
Generally, its obvious they have feelings for someone - they're just too shy to admit it, so they cover it up with insults, physical attacks or making it seem that something isn't a big deal (even though they really think it is - like an indirect kiss for example)
When closer friends point it out, they'll often blush and stutter:
"W..what?! There's no way I could love J-Jony, where d-did you get that crazy idea from!?"