How did XOXO come to mean kisses and hugs?

One scholar theorized that at some point during medieval times, the letter X – the first Greek letter in the name “Christ,” and which also looks like a Christian cross – expanded in usage to symbolize other things. Letters in medieval times were often sealed with an X, a kiss of faith, one could say. The reference might also explain why Christmas is sometimes shortened as Xmas. Through some unknown mechanism, the representation of X as a kiss for Jesus Christ came to have a more general connotation.

The first known possible use of the letter X to represent a kiss came in 1763 when naturalist Gilbert White wrote "I am with many a xxxxxxx and many a Pater noster (Our Father) and Ave Maria (Hail Mary), Gil. White." Some say that White did not mean kisses, but instead meant blessings, but the connection to written letters and positive feelings is there, in any case.

Former U.K. Prime Minister Winston Churchill sometimes ended his letters with X’s. "Please excuse bad writing as I am in an awful hurry. (Many kisses.) xxx WSC," he once wrote.

Some theorize that non-English speaking Jewish immigrants first arriving to the U.S. sometimes signed their name with the letter O, not being "Christian enough" to use an X, and thus, XOXO was born.

Happy Valentine’s Day from Government Technology.
XOXO