THESAURUS
Billion
a billion, a crore, a lakh, a million, a myriad, a nonillion, a quadrillion, a thousand, a zillion, astronomical number, googol, googolplex, infinitude, infinity, jillion, large number, milliard, trillion, zillion
ROGET THESAURUS
Billion
Five
N
five, five, cinque, quint, quincux, six, half-a- dozen, half dozen, seven, eight, nine, three times three, dicker, ten, decade, eleven, twelve, dozen, thirteen, long dozen, baker's dozen, quintuplet, twenty, score, twenty-four, four and twenty, two dozen, twenty-five, five and twenty, quarter of a hundred, forty, two score, fifty, half a hundred, sixty, three score, seventy, three score and ten, eighty, four score, ninety, fourscore and ten, sestiad, hundred, centenary, hecatomb, century, hundredweight, cwt, one hundred and forty-four, gross, thousand, chiliad, millennium, thousand years, grand, myriad, ten thousand, ban, man, ten thousand years, banzai, lac, one hundred thousand, plum, million, thousand million, milliard, billion, trillion, five, quinary, quintuple, fifth, senary, sextuple, sixth, seventh, septuple, octuple, eighth, ninefold, ninth, tenfold, decimal, denary, decuple, tenth, eleventh, duodenary, duodenal, twelfth, in one's 'teens, thirteenth, vicesimal, vigesimal, twentieth, twenty-fourth, vicenary, vicennial, centuple, centuplicate, centennial, centenary, centurial, secular, hundredth, thousandth.