.'s Very Own, KTLA is Southern California's source for Los Angeles-area breaking news, streaming live video, traffic and weather in ., Orange and Ventura counties, plus the Inland Empire and Define 5. 5 synonyms, 5 pronunciation, 5 translation, English dictionary definition of 5. Noun 1. 5 - the cardinal number that is the sum of four and one cinque, fin, five, fivesome, Little Phoebe, pentad, Phoebe, quint, quintuplet, quintet, V... 5 - definition of 5 by The Free Dictionary.