The antonym of a goft is a gift. 

For example, if we get a raise, we would think of that as a gift. Typically, however, if we're fired, we think that is a goft (something unwanted).

Another example, if a woman learns that she is pregnant and she wanted to get pregnant, then that will occur as a gift. If she didn't want to get pregnant, it is more likely to occur as a goft.