A form of laughter used by the English actor Tom Hiddleston. Often accompanied by throwing ones head backwards and showing as much teeth as physically possible. Used commonly by his fans, the 'Hiddlestoners' on social media websites such as tumblr. If you are a fan, the written form of laughter is enough to connect it to Hiddleston.
When you have nothing else to say, but you want to let the person know I heard you. OR When you hear something you like and words can not express the thing you feel. Pronunciation(do this while sticking your tounge out) Eh-heh. Stick your tongue out where the hyphen is.
Note: This word is so cool, it doesn't even have a definition. It can be used in question or statement forum. Also, while using this word, imagine yourself as a dolphin getting stoned ontop of a cloud.