Katie
KAY-tee
A cheerful Scottish diminutive of Catherine, ultimately meaning “pure.”
Meaning
Katie is a familiar Scottish pet form of Catherine/Katharine. The older name ultimately comes from Greek, and the excerpts connect it with the sense “pure.” In the 19th-century sources, Katie is treated as one of the contracted and diminutive forms of Catherine, alongside Kate and Kitty.
Origin
ScottishGreekfeminine
Fun fact
One excerpt specifically calls Katie the Scottish form, while noting that Kitty was once more common in the previous century.
Confidence: sourced. Sources: History of Christian Names, Praenomina; or, the etymology of the principal Christian names of Great Britain and Ireland.