xoxo hugs, kisses and SWAK

When and why did x's and o's become a symbol for hugs and kisses?

xoxo (generally lowercase letters) is a way to express love or good friendship at the end of a written letter - and now in email and SMS text messages.

Which letter represents which action? That is not actually clear, but the custom of placing "X" on envelopes, notes and at the bottom of letters to mean kisses dates back to the Middle Ages.

The symbol x is the letter taw in early Hebrew (and in Ezekiel, a mark set “upon the foreheads” of men) and chi in Greek. A Christian cross was used on medieval documents or letters to mean faith and honesty. It can still be seen on Medieval churches as a symbol of Christ and is why we sometimes see Christmas written as Xmas.

The Chi Rho is one of the earliest forms of christogram, and is formed by superimposing the first two (capital) letters chi and rho (ΧΡ) of the Greek word "ΧΡΙΣΤΟΣ" = KRistos = Christ to produce the monogram.

It is said that the pronunciation of the letter "X" in Spanish, though generally transliterated as equis, sounds like a native Spanish speaker saying "a kiss" in English.

The x also became the signature of choice in the Middle Ages since most of the common people could not read or write. A literal kiss would be placed upon the cross of a letter by the signer as a display of their sworn oath. Documents sealed with an x embossed in wax or lead (letters, books, oaths of political and economic fealty between kings and their vassals)were "sealed with a kiss.”

Much later, the acronym SWAK became popular during World War I for soldiers to imprint on their letters home.

There is speculation that the use of o may be of a more modern American origin. When arriving in the United States, Jewish immigrants, most of whose first language was Yiddish, would use an 'O' to sign documents, rather than the Christian X as a sign of the cross. Immigration inspectors called anyone who signed with an “o” “a kikel [circle in Yiddish] or kikeleh [little circle], which was shortened to kike,” and eventually took on a derogatory meaning.


Still, the origin of O as a hug and the combining of X and O is debatable.

Some interpret X as the crossed arms of a hug and O as the puckered lips of a kiss. How about X representing the four lips of a kiss and O the four arms of a hug?

The Oxford English Dictionary states that X is "used to represent a kiss, esp. in the subscription to a letter."

Some sources say that, based on the pronunciation of the letters, X sounds like 'kiss' and O sounds like 'hold', as in 'I hold you'.