A gigaannum, usual symbol Ga, is a unit of time equal to one
Another word more narrowly used to mean a billion years is "aeon" (eon).
it is called an eon
300,000,000,000 in word form is three hundred billion.
eon
One seven letter word, One two letter word and a five letter word, One three letter word and a four letter word, One three letter word and two two letter words, Two three letter words, Three two letter words, A two letter word and a four letter word, A six letter word, A two letter word and a three letter word, A five letter word, Two two letter words, A four letter word, A three letter word, or A two letter word.
I've is a three letter word. I'll is another three letter word.
Imp is a three-letter word for rapscallion.
A three letter word for help is aid.
A three letter word for a summit = Top.
A three letter word for gender is sex.
A three letter word for debt is owe.
Three billion.
Three hundred billion