look up any word, like darude - sandstorm:
A number, 1,000,000,000,000,000,000 or 10^18.
There are a quintillion drops of water in the lake.
by 5'1"Racer April 29, 2005
A large number. Comes after quadrillion.
It has 21 zeros

quint- (“five”) + -illion; ie the fifth power of a million, 10.30.
After Quintillion comes sextillion, then septillion ect.
by sharks554 September 25, 2011