The prefix "dis-" denotes negation, reversal, or separation. Some common synonyms for this prefix include "un-", "non-", "anti-", "contra-", and "de-". The prefix "un-" is used to negate or undo something, like unhappiness or unwrap. "Non-" is used to indicate the absence or lack of something, like nonfiction or nonstarter. "Anti-" and "contra-" are used to express opposition or against something, like antiwar or contradict. Lastly, "de-" is used to reverse or undo an action, like defrost or decaffeinated. These synonyms can be used interchangeably with "dis-", depending on the context and intended meaning of the word.