Wiktionary
n. An opinion which follows the outcome of the majority of the court, but might arrive there in a differing manner.
WordNet
n. an opinion that agrees with the court's disposition of the case but is written to express a particular judge's reasoning
Wikipedia
In law, a concurring opinion is a written opinion by one or more judges of a court which agrees with the decision made by the majority of the court, but states different (or additional) reasons as the basis for his or her decision. When no absolute majority of the court can agree on the basis for deciding the case, the decision of the court may be contained in a number of concurring opinions, and the concurring opinion joined by the greatest number of judges is referred to as the plurality opinion.
As a practical matter, concurring opinions are slightly less useful to lawyers than majority opinions. Having failed to receive a majority of the court's votes, concurring opinions are not binding precedent and cannot be cited as such. But concurring opinions can sometimes be cited as a form of persuasive precedent (assuming the point of law is one on which there is no binding precedent already in effect). The conflict in views between a majority opinion and a concurring opinion can assist a lawyer in understanding the points of law articulated in the majority opinion. Occasionally, a judge will use a concurring opinion to signal that he or she is open to certain types of "test cases" that would facilitate the development of a new legal rule, and in turn, such a concurring opinion may become more famous than the majority opinion in the same case. A well-known example of this phenomenon is Escola v. Coca-Cola Bottling Co. (1944).
Usage examples of "concurring opinion".
Stu had gone privately to Glen, had gotten a concurring opinion, and the experiment had been tried.
When you come to a difficult decision, such as how much of your resources must be allocated to which tasks for maximum effect, you need a concurring opinion.