look up any word, like wyd:
 
2.
A lovely young lady that seems demure, but she speaks with a foul mouth.

A reaction to bad news that is characterized by at first seeming calm and accepting but quickly turns into vulgar language and shouting. Usually executed by an emotionally unstable person.
Dude did you hear that girl? By the looks of her I thought she was all sweet but then she started swearing like a sailor.

I know she's such a Siham.

----------

I just told him there was no milk left and he seemed cool about it, but then like 2 seconds later he starts screaming his balls off.

He pulled a Siham again? We need to get him checked out.
by raaawwwwrrrrrrrrrr May 05, 2011
 
1.
a girl that guys would find sweet, romanctic and will have a long lasting relationship
SIHAM(booty,hot,sexy)
by yeah4u May 30, 2011