No, if 2 things are in evidence:
- the crab dip has mayonnaise in it
- the crab was previously frozen
When it comes to seafood it's best to err on the side of caution. If you don't know if the crab meat was previously frozen then throw it in the garbage. Better to lose a few dollars to the garbage can than spend more at the doctor! The rule for seafood: If it's been previously frozen then don't freeze it again because of the potential for excessive bacterial growth.
Here's more to consider:
What if the crabmeat is fresh or canned and the only oil in it is olive oil, canola oil or clarified butter? Then the answer is YES you can freeze it. Most crab dip is made with mayonnaise which has eggs in it and mayonnaise does not freeze well.
Remember, fresh seafood it only safe for about two days. If you desire to freeze it, do so on the day you buy it for optimum flavor and food safety to be retained. Just remember to freeze for a few days