Condonation appears to be an antonym or opposite of condemnation.    Unfortunately, it seems to imply that an action or action is being condoned, which would mean it is being accepted, but it is merely being overlooked or ignored, without the action or offense being condoned or accepted.   

The word "condonation" comes from the Latin word condōnātiōn-em and has been used in English since the early 1600s. The word "condone" comes from the Latin verb condonare, which is a combination of the prefix con- and the word donare. 

I admit that this is a word I've never used and don't recall ever hearing or reading. That is until now. Thank you @Myr for taking my vocabulary into unknown territory. I'm not sure if I love you or hate you.

The searching I did indicates that this is one of those words which rather than being in general use is mainly used in a particular context, and in this case legally.  While it can simply be condoning someone's behaviour it can also result in being legally 'hoist with your own petard'. For example an employer who condones or overlooks theft by and employee, then not being able to take legal action again the employee for theft on a later occasion. This is condonation in the legal sense, although @sandrewn may see it as Karma.

I was interested that a number of example I came across related to divorce proceeding, and not being able to use as grounds for divorce things that had previously been condoned. Australia has a process referred to as "no fault" divorce. A divorce can be granted if the couple live separately for at least 12 months and that the marriage has broken down and there is no reasonable chance they will get back together. Very few end up in court.    

I seek condonation for such a long post. Love this blog.