This is an English word that has come to mean a lot of different things in French. It's mostly used as an adjective, as in "je suis speed, moi." It can mean rushed, fast, quick, stressed, bothered, excited or in a hurry (and the list keeps on expanding). I blame the movie Speed for this particular addition to the language. Are you speed?
This just in: it's a verb, too! I just heard "j'ai speedé" yesterday. One word, many uses.