It doesn't just mean dislike at all. It will come from some Greek word meaning, "fear". Just about all English words with "ph" in them come from Greek words, just saying like. Apart from phishing, I'm guessing.
The word phobia comes from the Greek: φόβος (phóbos), meaning "aversion", "fear", or "morbid fear"
or mid 19th century: perhaps an alteration of the archaic noun puff in the sense 'braggart'. **** wrong post
The original Greek word didn't mean aversion though, the English language made it that way, they bastardised the word.
Like we do with all words - that's how language works. The ambulo- bit in ambulance, ambulocetus etc comes from the Latin verb ambulare (I knew this Higher would come in useful at some point). Ambulare = to walk.
Unless you're French, in which case the language is enshrined in law and can only be added to by the virtue of charters or amendments whereas we make words up all the time and within a year or two, it's in Oxford dictionary. I call the phenomenon "Braxapparance", let's get this word into the Oxford Dictionary for 2016!