blue moon

基本解釋

You shouldn't lose this once-in-a-blue-moon chance.
你不應(yīng)該錯(cuò)過這個(gè)難得的機(jī)會(huì)。
How could you miss such a once-in-a-blue-moon chance?
你怎么能錯(cuò)過這個(gè)千載難逢的機(jī)會(huì)呢？
Faced with the once-in-a-blue-moon business opportunity provided by the Olympic Games, many non-Olympic sponsors should take the strategies of non-Olympic marketing.
面對(duì)千載難逢的奧運(yùn)商機(jī)，眾多的非奧運(yùn)贊助商應(yīng)該采用非奧運(yùn)營銷的策略。

Secretary of State James Baker -- in the political equivalent of a "blue moon" -- admitted recently that President Bush and he had erred in appeasing Iraqi strongman Saddam Hussein, a policy that contributed substantially to the present Persian Gulf crisis.
CENTERFORSECURITYPOLICY: Which side will we be on?
Maybe it's time (once in a blue moon) for a high-level bipartisan commission--televised and transparent--to review the science, the costs and the regulatory processes, taking into account the national interest.
FORBES: A No-Lame-Duck Growth Agenda
The professor and the policeman's beers are equally symbolic, Pirko says - Red Stripe with its Jamaican pedigree, and Blue Moon striving for craft beer credibility, though it's actually made by Coors.
NPR: What Brands Will Be Served At Beer Summit?

the second full moon (= the time when the moon is shaped like a complete disc) in a month, that appears around every two and a half years