Variety.
One synonym for the word "foreign" is "international." This term is often used to describe things that are from or relate to other countries.
A synonym is a word that has the same meaning as another word.
electric switch, electrical switch, control, controller
a familiar word that means the same as an unfamiliar word
Diglossia refers to two or more different forms of the same language. A synonym for diglossia is "dialect." An example would be the English and American dialects, because both groups are still speaking English.
Variance, range, assortment, variety, medley, distinction... multiculturism
The synonym is the term from French : rendezvous.
The knowledge gap synonym for the term "information deficit" is "knowledge disparity."
miserliness
An informal synonym for the term optimal is the word ace. Ideal is also a good synonym, as well as matchless. There are a lot of other synonyms that can be found in a thesaurus or online.
Multiculturalism is often used in conjunction with the term diversity.
adjudicator, bench, court, judge, jurist, justice
There is no precise synonym for cyborg, however, the term android has a similar meaning.
math
Positive stress
miserliness
Credibility