A million, million, millions... as in:
1, 000,000, 000,000, 000,000 or 10^18
...from tri as in three.
It is lazily commonly missused for a million
millions, which is in fact a billion
, from bi as in two (...and not a thousand million
You see, a tricycle
does not have two wheels and a bicycle
does not have one and a half wheels.
A trillion dollars is a million, million, millions of dollars and a billion dollars is a million, millions of dollars. A thousand million dollars is $1,000, 000,000.