Blue moon (Once in a)


      • infrequent occurrence
        Referring to something that happens very rarely or once in a long while

      • something impossible
        Emphasizing that something is highly unlikely or impossible to happen

    Examples of Blue moon (Once in a)

    • In a decade, Emma has received a promotion twice, but the third promotion is a real blue moon - it's once in a lifetime opportunity.

      The expression 'blue moon' is common these days to describe a rare occurrence that doesn't happen frequently. Usually, it refers to an additional full moon appearing in a calendar month, which takes place about once every two to three years. In Emma's case, blue moon is not about the full moon, instead, it is about a promotion which Emma is looking forward to, as she has not received any promotion in a decade except twice. In other words, this promotion is a rare event, and it may not happen again in Emma's lifetime.

    • The CEO's decision is a genuine blue moon for our team, as we haven't witnessed such an influential change in our company in years.

      The speaker implies that the CEO's decision is an incredibly rare and significant occurrence that happened unexpectedly. The team hasn't encountered such a profound change in years, and it is most probably a remarkable occasion that won't happen again in a long time.

    • I've been in this business for years, and producing a top-rated film is a blue moon for me, and I'm taking advantage of this opportunity to show the world what I'm capable of.

      The speaker means that creating a highly-ranked movie is an extraordinary happening that is not frequent in his career. Since the speaker has many years of experience in the film industry, it is evident that making a blockbuster movie is not something that happens all the time, and it is, therefore, a rare occurrence. The speaker then explains that he wants to capitalize on the situation and demonstrate his skills to everyone.

    • The producer announced the casting of a famous actor in the movie. It's a real blue moon for us as we've been trying for years to cast him for our films, but he has always declined our invitations.

      The phrase 'blue moon' is used in an interesting way that shows how this rare occurrence can impact multiple parties or circumstances. The speaker and his team have been endeavoring to cast the renowned actor in their films for years, and it has not panned out despite their efforts. This unexpected announcement of the actor's presence in their movie can be considered as a spectacular turn of events or an incredible chance. The speaker further clarifies that this is a rare probability since they've been attempting to acquire the star for quite a while but failed.

    • The weather channel reported a blue moon last night - a rarely seen event that usually occurs only once in every 2-3 years.

      A blue moon is the second full moon in a calendar month. The phrase "once in a blue moon" implies that something occurs rarely, almost never.

    • I've been working on this project for an entire year, and finally it's finished. It's a blue moon that it's come out this well!

      The speaker is surprised and pleased by the success of their project, which is an unexpected outcome, as the task was challenging and time-consuming.

    • The company has been losing money for months now. We sure hope that our marketing strategy will turn things around and bring back some profits soon. Blue moon, I'd say!

      The speaker is not optimistic about the company's financial situation and uses the saying "blue moon" to express their doubts about a positive outcome.

    • Our team's performance has been outstanding lately. It's a true blue moon that everyone is working so hard and effectively towards our goals.

      The speaker is surprised and impressed by the high level of commitment and productivity of their team, which is quite unusual and rare.In each example, the idiom "Blue moon (Once in a)" is used to signify a rare occurrence or an unlikely result. It adds an extra layer of interest and a literary touch to the sentence.


    The idiom "blue moon" is commonly used to describe events or situations that happen very rarely or are almost impossible to occur. It is often used to emphasize the infrequency or unlikelihood of a particular event or circumstance.

    In some cases, "blue moon" can also refer to something that is highly valued or cherished due to its rarity. For example, a collector may refer to a rare item as a "blue moon" find, indicating its value and scarcity.

    Origin of "Blue moon (Once in a)"

    The origin of the idiom "blue moon" dates back to the 16th century, where it was used in medieval literature to describe a rare event. The earliest known usage of the phrase can be found in a pamphlet from 1528 where it was used to describe a rare occurrence of the moon appearing blue in the sky.

    However, the modern usage of the idiom is believed to have originated in the 19th century when the phrase "once in a blue moon" was first recorded in a book by Reverend Thomas Dick. It is speculated that the phrase may have been derived from the older expression "until a blue moon," which was used to describe a very long time.

    The "blue moon" itself is a rare astronomical event that occurs when there are two full moons in a single calendar month. This phenomenon happens approximately every two and a half years, giving rise to the idea that something that happens "once in a blue moon" is a rare and special occurrence.