(redirected from 21 AD)
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Noun1.21 - the cardinal number that is the sum of twenty and one21 - the cardinal number that is the sum of twenty and one
large integer - an integer equal to or greater than ten
Adj.1.21 - being one more than twenty21 - being one more than twenty    
cardinal - being or denoting a numerical quantity but not order; "cardinal numbers"
References in periodicals archive ?
THE NEW CENTURY 21 AD CAMPAIGN, which increased calls to CENTURY 21's toll free 1-800-4-HOUSES four-fold during its first week and will, over the course of the year, reach almost 100% of American homes 28 times -- nearly twice the number of consumer impressions the company achieved last year.
The ads are expected to reach 95 percent of adults, with an average of 21 ads shown by the end of the eight-week campaign -- for a total of 2.
By the end of the launch campaign's eight-week run, reach and frequency jumps to 95 percent of adults viewing an average of 21 ads for the Sprint Store, or more than 2.