just hate mean... 싫어, 싫다 silja explained very well.

Well, it depends whether you mean the verb "to hate" or the noun "hate". 증오 is a noun that means "hate, hathed, detestation". 증오하다 means "to hate, to detest". It's pretty strong word... Verb 싫어하다 means "to hate, to dislike". It not that radical than 증오하다. So if you want to say that "I don't like X" you say "X을/를 싫어해요".