Unary. Binary. Unicycle. Bicycle. Tricycle. Trinary.

1. Is there a difference between Trinary, Ternary (in operator specific context).

Trinary is a synonim for Ternary.

2. Why is Trinary used primarily in the Camel.

Why do people write Color instead of Colour? It doesn't really matter now does it.

3. How could two very knowledgeable people not know of such a term.

?????????

4. Possibly some background history on the terms themselves.

What? Get a thesaurus.