Yamshahhar

A word used exclusively by Southern Lebanese people as a reaction to an unexpected event or news

An Arabic phrase used mainly in the Lebanon as a reaction when receiving news about a very bad incident (death, accident, ..), or as an exaggeration to a not-so-bad incident, like when kids break something or ruin the place.
It's usually used by mothers and elderly women.

Words used in phrase:
Sh'har: Is the black dirt one gets when s/he touches charcoal or the bottom of a dirty cooking pot or pan.
Mshahhar (mas.)/Mshahhara (fem.): Is a person whose face has been smudged with Sh'har (the black dirt)
Ya: O. Used in Arabic to call upon someone; e.g. O Man, where are you? O Alex, where did you hide my book?

So Yamshahhar, literally means "Oh you whose face is smudged with black dirt!"

Background:
In the old days, when someone passed away, his/her close relatives (especially women; mother, wife, sister..) would smear their face(s) with black dirt coming from charcoal or the bottom of cooking pots. This was to show extreme sadness about what had befallen them.
With time the phrase Yamshahhar/Yamshahhara became used to express extreme feelings of shock and sadness about a bad incident, though the act of smudging ones face stopped. Now, this phrase is usually used by the elderly, especially women, although most people who use it do not know the meaning of the words or why it is coined like this (like many idioms in Arabic and other languages).