UN

To delete a friend from one's network on a social media site. I can't believe he unfriended me just because I disagreed with an article he posted.

Someone or something that provides a great benefit, has done very good work, has performed some heroic deed or function, etc., but has not received the credit or recognition they deserve. It's the volunteers who are the real unsung heroes of this event. They're the ones who put in countless hours without pay to ensure that everything runs smoothly from beginning to end. The company is known for their expensive smart devices, but its their subscription-based cloud storage that has been their real unsung hero, responsible for over 45% of their annual profit for the last four years.

Fig. a hero who has gotten no praise or recognition. The time has come to recognize all the unsung heroes of the battle for low-cost housing.