"For lack of a better word" doesn't seem to apply to Arabic speakers as we tend to do quite the opposite in conversations. Sometimes certain *unoriginal* words are used to describe traits, situations, illnesses, and the like ... despite the fact that the dictionary has real terms for those things. 

For example, in the Arab world, many people prefer to use the term "al 3arees" which is Arabic for "the groom" to refer to a woman's boyfriend. The latter is, unfortunately, still seen as a taboo idea in many Arab societies. Because God forbid a woman goes out on a date with a man before he pulls out the ring and gets on one knee, right?

In many Arab societies, double standards exist when it comes to the dating world. Men are expected (and praised) to have experience in the field of dating, but the same doesn't apply to their counterparts. Women must deal with an extra layer of pressure (on top of the countless 3a2beliks) when dating in the Arab world. First, society must rate the man as "3arees" material. Second, the couple must have started planning the wedding before their first date or that would mean the man is "just playing." Such beliefs not only perpetuate the patriarchal systems in place but also treat women as minors who have no clue what they're getting themselves into. It's backwards at best and misogynistic at worst.

Well, moving on to my actual point ...

Aside from the boyfriend-3arees replacement, there are many words that are often switched out for terms that are deemed more comfortable (sometimes more vulgar) to one's tongue. In other cases, concrete remedies or items are switched out for alternatives invented by Arabs themselves. 

Here are just a few examples:

On cancer

On smartness

On bravos

On policing women's dress choices

On burn remedies

On doctor (aka teta) prescriptions

On nightmares