A “Hail Mary pass” is, in American football, a very long forward pass, made in desperation and with a very low chance of success. The term was coined by Dallas Cowboys quarterback Roger Staubach in December 1975 when questioned about his game winning but improbably long pass. His response to the question was, “I closed my eyes and said a Hail Mary”.
Irises, a genus of approximately 300 species of showy flowering plants found around the world, derive their name from the Greek word for rainbow (Iris is also the name for the Greek goddess of the rainbow).
A group of owls is called a “parliament”.
In Japan it’s a common practice to rub very cheap waribashi (wooden chopsticks that you need to break apart) together in order to smooth them out and remove splinters. As such, it is considered offensive to do so when offered good quality waribashi in someone’s home as it indicates you think the chopsticks are cheap, and therefore it is an insult.