BCNU, commonly used as an abbreviation for "be seeing you," is an informal way of saying goodbye. This phrase is often used casually among friends and associates. However, if you are looking for some synonyms to mix things up, there are a few other options available. Some of these synonyms include "see ya later," "farewell," "adios," "toodles," "cheerio," "au revoir," "goodbye," "hasta la vista," "so long," and "take care." Regardless of which synonym you choose, the sentiment remains the same- wishing the other person well until the next time you meet.