Greatest is an adjective. It has no plural because it is not a noun.
tattarrattat
antidisestablishmentarianism
Yes, "greatest" is a real word. It is the superlative form of "great," used to describe something that is the highest in quality, degree, or magnitude among a group. For example, one might refer to the "greatest athlete" to indicate the best among all athletes.
SD max
If your question is correct, there is no such thing as that; if it isn't, then it's either the least common factor, or the greatest common denominator.
The word greatest has two syllables. Great-est.
Best, or largest.
Greatest is an adjective. It has no plural because it is not a noun.
laid
That was the greatest thing I've ever seen. His was the greatest act of sacrifice anyone had heard of.
tattarrattat
God (Allah)
antidisestablishmentarianism
Best and Greatest
The GCF or greatest common factor.
Abuse of power.
dominant