Koss-ommak: two words , the first : koss means "Pussy" in most of the Arabic countries and or/accents.
The second : Ommak means your mom in all Arabic countries and/or accents.
In the Arabic countries : insulting the Religion and/or Mother is the maximum you can do when you need to offend someone , since most of the people share the same religion , it is the most widely used word to offend others.

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed